Skin neoplasms in Long Evans rats
A. ESFANDIARI, J. L. LEE, A. VAKILI and S. TEKLEHAIMANOT
Charles R. Drew University of Medicine and Science, Los Angeles, California, USA
In this study, we report on 25 cases (83%) of skin neoplasms in a group of 30 Long Evans (LE) rats. The rats were obtained from Charles River Laboratory and were approximately 10 weeks old at the start of a behavioural study. After 9 months (approximately 11 months of age), 30 rats (15 males and 15 females) were selected as a control group for student observations and training. These rats were housed in individual cages. Six months later, or at approximately > 17 months of age, skin tumours were found in 13 female (87%) and 12 male (80%) rats. Skin tumours in male rats were located on the dorso-medial aspect of the left hind leg. Skin tumours measured 1–2 cm in diameter. In male rats, histological examination of tissue revealed a well-demarcated cystic dermal mass composed of neoplastic squamous epithelial cells compatible with keratoacanthoma. These neoplasms were derived from hair follicles and were considered abortive malignancies of the prototype of cutaneous pseudomalignancies. In female rats, both keratoacanthomas and fibroadenomas were found. The latter were located on the forearms. The fibroadenomas were well-demarcated multilobulated tumours consisting of lobules made up of diffusely secretory acini. These findings indicate higher rates of skin tumours among LE rats compared to the results reported by other researchers.
The use of terbinafine for the treatment of dermatophytosis
Charles Small Animal Clinic, Taipei, Taiwan, Republic of China
In Taipei, the author has noted cases of dermatophytosis that are highly resistant to ketoconazole and itraconazole. There is an increasing need for safe and effective new drugs to treat dermatophytosis. Terbinafine (Lamisil®Novartis) is an allylamine fungicidal agent that has been found to be very effective in the treatment of human dermatophytosis. Terbinafine inhibits squalene epoxidase, an early step in the pathway of ergosterol synthesis, which results in fungal cell death. The active site is unassociated with the cytochrome P-450 system and terbinafine does not affect the metabolism of hormones like other azole antifungal agents. The purpose of this study was to confirm the efficacy and safety of terbinafine in the treatment of small animal dermatophytosis. Forty-one dogs, 24 cats and eight pet rodents with dermatophytosis were treated with terbinafine at a dose of 10–30 mg kg−1 once daily. No adverse effects from the drug were noted during or after treatment. Ten dogs and three cats in the highest dosage (30 mg kg−1) group had their liver function tests monitored during therapy. Serum ALT concentrations were mild to moderately elevated in 4/10 dogs and serum ALKP concentrations were mild to moderately increased in 2/10 dogs. All other serum chemistry values were with normal laboratory ranges. The mean length of therapy was 7.6 weeks (3–18 weeks) for dogs, 8.9 weeks (4–12 weeks) for cats and 6 weeks for rodents. The findings of this study suggest that terbinafine can be used safely and effectively in dogs, cats, and rodents with dermatophytosis. Supported by a grant from The Association of Veterinary Dermatology-Taipei.
Notoedric mange in hamsters: comparative therapy with subcutaneous ivermectin or oral moxidectin
L. BECO, A. PETITE and T. OLIVRY
Clinique Vétérinaire, Spa, Belgium; College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
The purpose of this trial was to compare the efficacy of three treatment regimens for notoedric acariasis in hamsters. Thirty hamsters were diagnosed with Notoedres infestation based on clinical signs and skin scrapings. They were separated into three groups of 10 animals per group. Group 1 was treated with ivermectin at 400 μg kg−1, subcutaneously, once weekly for 8 weeks. Group 2 was treated with moxidectin at 400 μg kg−1 orally once weekly for 8 weeks. Group 3 was treated with moxidectin at 400 μg kg−1 orally twice weekly for 8 weeks. Before, and each week during the study, skin lesions were scored based on the degree of crusting, erythema, hyperpigmentation and excoriations at various body sites. Skin scrapings were performed on the ear pinnae. In all three groups, clinical scores were significantly lower at 4 and 8 weeks post-treatment than before therapy was initiated (nonparametric repeated measure anova, P < 0.0001). After 4 and 8 weeks, there was no significant difference in the efficacy between groups, as assessed by a nonparametric anova (P > 0.75). At the end of treatment, however, negative scrapings were obtained only in 60%–70% of the animals in each group. Treatment with oral moxidectin proved easier to administer than ivermectin injections. Three hamsters died during this study but a direct relationship with treatment proved impossible to demonstrate. Results of this trial suggest that oral moxidectin could be considered as an alternative to ivermectin for the treatment of notoedric mange in hamsters. Based upon the results of this study, duration of therapy must extend beyond 8 weeks.
The value of the pinnal-pedal scratch reflex in the diagnosis of canine scabies
R. S. MUELLER, S. V. BETTENAY and M. SHIPSTONE
College of Veterinary Medicine, Colorado State University, Fort Collins, Colorado, USA; Animal Dermatology Clinic, Brisbane, Australia
The pinnal-pedal scratch reflex has been reported anecdotally to be helpful in the diagnosis of canine scabies. The purpose of this study was to evaluate the pinnal-pedal scratch reflex as an aid in diagnosing canine scabies. History, clinical examination and case-appropriate diagnostic tests were used to evaluate 680 dogs presented for nonresponsive or recurrent skin disease. The pinnal-pedal scratch reflex was assessed by vigorously rubbing the tip of one earflap onto the base for 5 s. The reflex was considered positive if the ipsilateral hind leg performed a scratching movement. A diagnosis of scabies was based on history, physical examination and either positive skin scrapings or resolution of skin disease after a scabicidal therapeutic trial and no relapse for at least 12 months. Of the 608 dogs evaluated, 20 dogs were excluded from the study because 12-month follow-up was not successful. Scabies was diagnosed in 55 dogs. Allergic skin disease was diagnosed in 385 dogs and various other skin diseases were diagnosed in the remaining 148 dogs. A positive pinnal pedal scratch reflex was present in 45/55 (82%) of the dogs with scabies. Forty of the dogs with scabies had pinnal dermatitis, 36 of 40 (90%) had a positive pinnal-pedal scratch reflex. A positive pinnal-pedal scratch reflex was noted in 33/533 (6.2%) of all other dogs. Based on these results, the specificity of testing for the pinnal-pedal scratch reflex was 92.8%, while the sensitivity was slightly lower at 81.8%. The positive predictive value was 0.57 and the negative predictive value 0.98.
A study on intradermal skin test reactivity to Substance P in clinically normal dogs and dogs with atopic dermatitis
R. MARSELLA and C. F. NICKLIN
College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
In people, neuropeptides, such as Substance P (SP), are involved in the pathogenesis of atopic dermatitis. The objective of this study was to evaluate intradermal skin test reactivity to injections of Substance P in clinically normal dogs and dogs with atopic dermatitis. Twenty normal and 20 atopic dogs were selected. Each dog received intradermal injections of SP (0.1, 0.5 and 1 n m), saline, and histamine. Reactions were evaluated for erythema and induration and a subjective score, on a scale from 0 to 4+, was given. Wheal diameters were also measured. Evaluations were performed at 3, 5, 10, 15, and 30 min after the injections. Data were analysed by the least square analysis of variance with all the main effects and interactions included in the model. Differences among group responses at various injection sites and measurement times were analysed using orthogonal contrast analysis. A P-value < 0.05 was considered significant. Subjective scores for SP reactions were significantly lower in atopic dogs when compared to clinically normal dogs. There were no significant differences in reactions when various concentrations of SP were compared. The wheal diameters for both histamine and SP injections were significantly smaller in the atopic dogs than in normal dogs. Reactions to SP were always smaller than histamine reactions. No erythema was seen with SP injections. These results are similar to the ones reported in human medicine, where a desensitization of target structures to abnormally increased levels of SP and histamine is hypothesized. Supported by a grant from Morris Animal Foundation.
Evaluation of the toxicity of topical enilconazole in cats
K. A. HNILICA, L. MEDLEAU and L. CORNELIUS
University of Georgia, College of Veterinary Medicine, Athens, Georgia, USA
Recent studies have demonstrated that enilconazole is effective in the treatment of dermatophytosis. The purpose of this study was to determine the relative safety of a topical enilconazole solution made from Clinafarm® EC. Twenty-two Persian cats from a breeding cattery infected with Microsporum canis were used in this study. Each cat was treated topically with 100 mL of 0.2% enilconazole applied every 3 days for eight treatments. Each cat was examined every 14 days for 60 days. Blood samples for complete blood counts and serum chemistry profiles were obtained from 20 cats on day 0, from seven cats on day 14 and from 19 cats on day 28. Throughout the study, the cats maintained excellent appetites, activity levels, and normal social interaction. The hair coat of white cats developed a smoky discoloration. Immediately post-treatment, two cats began drooling which resolved when the cats were prevented from grooming their wet hair. One cat developed rear limb muscle weakness after four treatments that resolved spontaneously after 1 week. On day 0, one adult female had a slightly elevated ALT concentration that was within normal laboratory parameters on day 14, but was elevated again on day 28. On day 14, another adult female had an elevated ALT concentration that was still present on day 28. A total of six cats developed elevated ALT concentrations by day 28 but remained clinically normal. Topical 0.2% enilconazole therapy was well tolerated in cats. Cats should be watched for clinical signs of liver disease and monitored with serum chemistries. Supported by the University of Georgia’s Comparative Medical Research Fund.
Primary hypothyroidism in a cat
J. C. DAIGLE, C. S. FOIL and K. WOLFSHEIMER
Veterinary Teaching Hospital and Clinics, Louisiana State University, Baton Rouge, Louisiana; Endocrine Diagnostics and Consultation, Baton Rouge, Louisiana, USA
This report describes a confirmed case of primary hypothyroidism in a cat and the validation of TSH concentration levels in the cat. A 5-year-old female spayed domestic shorthair cat was examined for lethargy and a nonhealing wound on the plantar surface of the left hock. Previous histopathological examination of a skin biopsy of the lesion revealed chronic ulcerative dermatitis. Cultures of biopsy specimens were negative for microbial growth. On clinical examination the following abnormalities were found: mild hypothermia (99.6°F), abdominal distention, dull mentation and a ‘puffy’ face with no evidence of pitting oedema, a poor hair coat with generalized fine white scale and partial alopecia of the tail. An apparent decubital ulcer was present on the plantar aspect of the left hock. An ACTH stimulation test was normal. TT4 and free thyroxine (fT4) concentrations were both low (TT4 = < 0.6 nmol L−1, normal = 12.3–43.5; fT4 = < 1.9 pmol L−1, normal = 17.2–45.6). TSH concentration was elevated (1.2 ng mL−1, normal = < 0.03–0.05, n = 8). TSH stimulation test revealed a low baseline (< 0.06 nmol L−1) with no evidence of stimulation at 4 or 6 h post-TSH. Based upon these findings, a diagnosis of hypothyroidism was made and 0.1 mg levothyroxine once daily was prescribed. Four weeks after starting therapy, the cat was more alert. A pre-and post-pill TT4 was within normal to high-normal range (pre = 24.5 nmol L−1 and post = 46.7 nmol L−1, normal = 12.3–35.7). Histopathologic studies of the thyroid gland were not performed to help determine the aetiology.
Evaluation of potential allergen cross-reactivity in canine atopic dermatitis based on 1000 intradermal skin tests
R. S. MUELLER, S. V. BETTENAY and L. TIDEMAN
Colorado State University, Fort Collins, Colorado, USA; Animal Skin & Allergy Clinic, Mount Waverley, Australia
In humans, cross-reactivity of closely related allergens has been evaluated by intradermal skin tests, Prausnitz-Kuestner extinction, Ouchterlony gel double immunodiffusion and RAST inhibition. The purpose of this study was to evaluate concurrent positive reactions of related vs. nonrelated allergens in canine atopy based on 1000 intradermal skin tests. Diagnosis of atopy was made based on history, physical examination and exclusion of differential diagnoses, such as adverse food reactions or scabies, by appropriate procedures. Skin test reactions were graded from 0 to 4. Reactions graded as 2, 3 or 4 (evaluation A) and 3 or 4 (evaluation B) were considered positive. Closely related allergens were selected based on reports of the presence or absence of cross-reactivity in human allergic disease. Select examples of closely related allergens included perennial rye grass (Lolium perenne) and cocksfoot (Dactylis glomerata), bent grass (Agrostis alba) and cocksfoot, short ragweed (Ambrosia elatior) and perennial ragweed (Ambrosia psilostachia), fat hen (Chenopodium album) and Mexican tea (Chenopodium ambrosioides) and the house dust mites Dermatophagoidesfarinae and D. pteronyssinus. Pine (Pinus spp.) and peppercorn (Schimus spp.), pine and birch (Betula spp.), sweet vernal (Anthoxanthum odouratum) and bent grass, couch grass (Cynodon dactylon) and perennial rye grass and short ragweed and fat hen were chosen as examples of pairs not showing cross-reactivity in human allergic individuals. Comparing the percentage of concurrent reactions in related allergen pairs with the percentage in nonrelated ones using a Mann–Whitney test, there was no significant difference (P = 0.6824 for evaluation A and P = 0.123 for evaluation B). This is evidence against marked cross-reactivity of the evaluated allergens in canine atopic dermatitis.
Commercial dry dog food in the North Central USA is not contaminated with Dermatophagoides house dust mites
T. A. SCHREINER and D. J. DEBOER
School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
Contamination of home-stored cereal grain food products with Dermatophagoides sp. house dust mites (HDM) was recently reported, along with anaphylaxis after consumption of these foods by dust mite-allergic people. We hypothesized that commercial dry dog food similarly could become contaminated, particularly if stored improperly, and eventually could contribute to allergic signs in dogs. Newly purchased bags of dry dog food (n = 30), from a variety of sources and manufacturers, and client samples of dry dog food (n = 50), stored under a variety of conditions, were obtained. Samples were finely ground, sifted, and extracted in aqueous buffer. Extracts were assayed for Dermatophagoides group II (Der II) allergen, a heat-stable component of both D. farinae and D. pteronyssinus, as a marker for presence of HDM. The assay was a two-site sandwich-type ELISA employing monoclonal antibodies against Der II (sensitivity, 40 ng Der II g−1 food). Der 2 allergen was not detected in any of the 30 newly purchased or 50 stored samples tested. Positive control samples consisting of house dust or dog food mixed with house dust, similarly extracted, and Dermatophagoides commercial allergen extract were positive for Der II in the same assay. We could find no evidence of HDM contamination in newly purchased or stored commercial dry dog food from the North Central United States.
Delusions of parasitism: case report
C. E. LARSSON, M. OTSUK and A. C. BALDA
Serviço de Dermatologia do Departamento de Clínica Médica da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Brazil
A delusion of parasitism is a phobic state found in people who believe that they are infested with a cutaneous parasite. People with this disorder report symptoms such as pruritus or a ‘crawling’ sensation under the skin that they attribute to movement of the parasites. The prevalence of this phobia-obsession is unknown. In the USA, there are approximately 3000 cases reported yearly. Recently, a middle-aged housewife presented to the FMVZ/USP with her two Siberian husky dogs. These dogs had been taken to two veterinarians who found them to be free of any dermatologic problems. She claimed that after contact with the dogs she became infested with parasites. She consulted an internist and a dermatologist who referred her animals to the veterinary hospital for further evaluation. Her major complaint was intense and episodic pruritus and a generalized crawling sensation under the skin especially around her waist and cervical regions. She attributed this sensation to the ‘movement of bugs under the skin’. Clinically, the animals did not show any cutaneous lesions. After being informed about the dogs’ healthy state she became irritated and frustated and she insisted they were the source of infestation. She showed us some ‘acquired lesions’ that consisted of well-demarcated areas of excoriations and localized dischromia on her lumbar and cervical regions. She brought us several paper boxes containing fragments of shed epidermis that she believed to be ‘live bugs’. At the present time, she is under psychiatric therapy using pimozida and is showing progressive clinical improvement of the dermatocompulsive symptons.
Canine leproid granuloma syndrome (CLGS) in Brazil (São Paulo)
C. E. LARSSON, M. OTSUKA, N. S. MICHALANY, S. R. PINHEIRO, S. M. SAKAMOTO and C. R. PEDRO
Serviço de Dermatologia do Departamento de Clínica Médica da Faculdade de Medicina Veterinária e Zootecnia e Faculdade de Medicina da Universidade de São Paulo, Brazil
Mycobacterial nodular granuloma was first reported in Brazil in 1990. Over the next 10 years, the Dermatology Service of Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Brazil diagnosed 12 cases of CLGS. The clinical and epidemiological findings of these cases are very similar to those reported in Australia and New Zealand. Both of these countries are similar to Brazil in latitude (20–40°) and both are approximately equally below the tropic of Capricorn. In these cases, direct smears of tissue and histological examination of skin biopsies using acid fast stains (Ziehl-Neelsen) made the definitive diagnosis. Attempts at isolation of organisms via Lowenstein-Jensen media and inoculation in hamsters were made. In addition, fixed material was subjected to PCR-RFLP analysis. The aetiological agent was found only via direct smears or histological examination of tissue. Ten of the dogs were purebreed, and interestingly six were boxer dogs. Eight of the 12 dogs were females. The majority of the cases occurred in either the summer (60%) or winter (20%). The affected dogs were between 2 and 13 years of age. Clinical signs were present between 1 and 48 weeks at time of examination. Dogs presented with unilateral (n = 3) or bilateral (n = 9) ear lesions, thoracic lesions (n = 1) or foot lesions (n = 1). Peripheral lymph node and internal organ involvement were absent in all cases. Cases were successfully treated with either rifampin subcutaneously or rifamicin topically or enrofloxacin subcutaneously.
Lack of efficacy of amitraz collars for the treatment of generalized demodicosis (GD)
C. E. LARSSON and M. OTSUKA
Serviço de Dermatologia do Departamento de Clínica Médica da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Brazil
Amitraz (9%) impregnated dog collars were introduced in Brazil in 1995 for the control of ticks and for the treatment of demodicosis. Due to the conflicting reports about the efficacy in the treatment or control of GD, the following clinical study was done. Amitraz collars were used to treat GD in 17 dogs. Ten of the dogs (59%) were pure-breed. Thirteen (76.5%) of the dogs were female and four (23.5%) were male. The dogs ranged in age from 3 to 16 months. Fourteen (82%) of the dogs had short hair. A diagnosis of GD was made by skin scrapings and mite counts were used to assess efficacy. The 17 dogs were divided into two groups. Group 1 consisted of six dogs with clinical pyoderma and GD. These dogs initially were treated with a 2.5% benzoyl peroxide shampoo, oral cephalexin, and wet dressings (potassium permanganate) until the pyoderma had resolved. After resolution of the pyoderma, the dogs were fitted with an amitraz collar that was changed every 3 weeks. Group 2 consisted of 11 dogs with GD and no pyoderma. These dogs were bathed in a 2.5% benzoyl peroxide shampoo and then fitted with an amitraz collar that was changed every 3 weeks. Dogs in both groups were examined every 2–3 weeks until cured; a cure was defined as three consecutive negative skin scrapings at biweekly intervals. Fifteen dogs completed the study. Five dogs all weighing less than 10 kg were cured. The protocol was unsuccessful in the other 10 dogs (67%). Based upon the findings in this study, amitraz collars are an ineffective therapy for GD.
The development and use of an ultra-violet block out canine body suit (UVBBS) for control of solar-induced squamous cell carcinomas
University of the Witwatersrand, Johannesburg, South Africa
Excessive exposure to ultra violet (UV) light may lead to solar induced squamous cell carcinomas. Bull terrier dogs and Staffordshire terrier dogs are popular pets in South Africa and squamous cell carcinomas are common in these breeds. One of the predisposing causes is the lack of pigmentation and/or protective hair on the abdominal regions of these dogs. This is problematic because these dogs commonly are ‘sun worshippers’ and bask in full sunlight, usually from an early age. Areas with excessive sun exposure develop chronic inflammation that leads to actinic keratosis and eventually, skin tumours. Veterinarians have had little success in persuading owners to keep their dogs inside between 8 a.m. to 5 p.m. when UV light is strongest. Protective body coverings (ultra violet block out canine body suits) were developed to protect the skin of these dogs and allow them to remain outside. The bodysuits are made of high quality, dark-coloured Lycra™ fabric treated with Rayosan™ that absorbs 98% of the UV radiation. The material is light, stretchable, and is machine washable. The body suit covers the dog’s body starting at the neck. The body suit drapes over the dog’s body and legs extending below the elbows and hocks. When the dog lies on its back the thorax and the abdomen are completely covered. The suit is designed so that there is cut-away space below the tail allowing female dogs to urinate and defecate. In addition, there is a detachable Velcro™ strap that allows male dogs to urinate without marking the suit. The body suit securely attaches to the dog’s collar with five loops. Dogs quickly adjust to wearing this protective covering. Self supported.
Safety of an experimental Microsporum canis vaccine in farmed foxes
L. K. BREDAHL, A. M. BRATBERG, I. T. SOLBAKK and A. LUND
Alpharma AS; National Veterinary Institute, Oslo; Agricultural University of Norway, Aas, Norway
Safety of an experimental vaccine against Microsporum canis, containing live and inactivated components, was evaluated in adult foxes and, subsequently, in cubs. Acute toxicity (10× recommended dose) was tested in two adults and two cubs. Sensitization (2× recommended dose, administered three times at 2-week intervals) was tested in three adults and three cubs. Local and general reactions were recorded the first 10 days and 5 days after each vaccination in the acute toxicity and sensitization tests, respectively. In a field trial, approximately 1000 cubs were vaccinated twice at 2-week intervals with the recommended dose. Out of these animals, 60 cubs were randomly selected and examined for local reactions at 4 and 6 weeks after the second vaccination. Animals with crusts at the injection site were observed until the crusts disappeared. Scrapings from the crusts and brush samples from the fur (McKenzie Brush Test) were inoculated onto mycobiotic agar plates. None of the animals in these studies had any general or acute local reactions attributable to vaccination. In the sensitization test, small spots with hair loss or crust formation at the injection sites were observed 2–4 weeks after vaccination. In the field trial, 32% of the examined animals experienced similar reactions lasting for 2–6 weeks. The live component of the vaccine was isolated exclusively in crust materials from the injection sites. The findings of the live component in crusts are in accordance with those from other live dermatophyte vaccines. To conclude, the vaccine is safe to use in foxes. This study was supported by the Norwegian Research Council and Alpharma AS.
Molecular characteristics of cutaneous papillomavirus from a case of canine pigmented epidermal nevus
C. TANABE, R. KANO, M. NAGATA, Y. NAKAMURA, S. WATANABE and A. HASEGAWA
Nihon University School of Veterinary Medicine, Kameino, Fujisawa Kanagawa; Department of Dermatology, Teikyo University School of Medicine; and Animal Dermatology Center, ASC, Japan
The purpose of this study was to investigate the molecular characteristics of cutaneous papillomvirus. In this study, the L1 gene of papillomavirus from a canine pigmented epidermal nevus (PEN) was cloned and sequenced. Amplification of the DNA sample with the L1 consensus primers yielded an expected fragment of approximately 450-bp. The nucleotide sequences of the fragment showed approximately 64% of sequence similarity to the L1 region of human papillomavirus isolate CP6108 and less than 57% sequence similarity to those of canine oral papillomavirus (COPV). In situ hybridization determined the presence of papillomavirus DNA mainly in the upper stratum granulosum of skin in this case. These results indicate that the canine cutaneous papillomavirus isolated from this PEN was genetically closer to human papillomavirus, rather than COPV.
Otic ivermectin in the treatment of feline Otodectes infestation
H. P. HUANG and Y. H. LIEN
Department of Veterinary Medicine, National Taiwan University; Azu Small Animal Clinics, Taipei, Taiwan
In this study, the efficacy of an otic formulation of ivermectin for the treatment of feline Otodectes infestation was evaluated. Thirty-two cats with naturally occurring infestations were used in this study. In addition, all 32 cats had failed to respond to an otic thiabendazole preparation. Otodectes infestation was confirmed via microscopic examination of ear mite debris. One part injectable ivermectin (Ivomect injection, 1% w/v MSD-AGVET, Haarlem, Netherlands) was diluted with nine parts of propylene glycol to make an otic preparation of 30 μg drop−1. Each cat was treated as follows. Two to four drops of the ivermectin solution (mean dosage 56 μg kg−1, range 28–126 μg kg−1) were placed into each external ear canal once daily for 21 days. Complete resolution of clinical signs was seen in all 32 cats after 21 days of treatment. No adverse reactions were noted in any of the cats. One cat did relapse 3 months after treatment. This cat was treated again with otic ivermectin but for 28 days. This cat has been free of clinical signs of ear mite infestation for more than 1 year. In this study, topical application of otic ivermectin at mean dosage of 56 μg kg−1 per day for 21 days was an effective treatment for feline Otodectes infestation and was not associated with any adverse reactions. The study was self-funded.
Susceptibility of Malassezia pachydermatis to econazole and ketoconazole
H. P. HUANG and H. F. KAU
Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
Malassezia pachydermatis is part of the resident flora of dog skin and is associated with various skin diseases. The purpose of this study was to evaluate susceptibility of M. pachydermatis to econazole and ketoconazole using a disc diffusion susceptibility test. Samples were collected from dogs with various skin diseases, and 103 isolates were tested. Malassezia pachydermatis was isolated using Sabouraud dextrose agar plates. The isolates were identified by gross and microscopic morphological characteristics. A suspension equivalent to a MacFarland No.2 standard was prepared in 2 mL of sterile distilled water. Using a sterile swab, agar plates were inoculated with the prepared suspension. Two discs, each containing 10 μg econazole or 10 μg ketoconazole, were placed on the Sabouraud dextrose agar plate. The plates were incubated at 37°C for 24–48 h. The annular radius of the zone of inhibition was measured in millimetres. In this study, an annular radius of > 10 mm was classified as susceptible. For econazole, 90.3% (93/103) of the isolates were classified as susceptible and 95.1% (98/103) of the isolates were classified as susceptive to ketoconazole. In conclusion, more than 90% of M. pachydermatis isolates were susceptible to econazole and ketoconazole using a disc diffusion susceptibility test. Based upon the results of this study, it is anticipated that either topical econazole or systemic ketoconazole should be efficacious in the controlling canine Malassezia dermatitis in vivo. The study was self-funded.
Double blind, placebo controlled, study to evaluate two miconazole leave-on conditioners to treat Malassezia dermatitis in dogs
R. MARSELLA, C. F. NICKLIN and J. NERBONNE
College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
Eighteen dogs with Malassezia dermatitis were entered in a double blind, placebo-controlled clinical trial to evaluate the efficacy of miconazole leave-on conditioners. Diagnosis of Malassezia dermatitis was based on clinical signs and cytological examination of the skin. Cytological preparations were made by direct slide impression on the skin or by using clear acetate tapes applied onto the skin. Slides were stained (Diff-Quik®) and examined under oil immersion (10×100). Yeast organisms were counted in 10 fields and the average number per slide was calculated. Once selected, dogs were randomly assigned to one of the following treatment groups: vehicle only, miconazole 1%, and miconazole 2% leave-on conditioner. Both owners and investigators were blinded to the treatment. Conditioners were used 3x weekly for 2 weeks and then twice weekly for two additional weeks. Owners scored pruritus daily, while investigators evaluated erythema, pruritus, and yeast counts once weekly. A scale of 0–5 was used to assess clinical signs (higher numbers indicating more severe clinical signs). At the end of the study, the number of yeast found on skin impression smears had decreased in all treatment groups. Over all times, the number of yeast in the vehicle treatment group was significantly higher than in both the miconazole treatment groups (P = 0.001 and P = 0.02 for 1% and 2% miconazole, respectively). The number of yeast, however, was not significantly different between the two miconazole treatment groups over all times (P = 0.24). Patient clinical scores (owner and investigator) significantly decreased at the end of the study but no difference was detected between treatments. Funded by Allerderm Virbac, Forth Worth, TX.
Cyclosporin-A decreases skin lesions and pruritus in dogs with atopic dermatitis: a prednisolone-controlled blinded trial
T. OLIVRY, C. RIVIERRE, H. A. JACKSON, K. M. MURPHY and C. A. SOUSA
College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina; Animal Dermatology Clinic, Sacramento, California, USA
The purpose of this study was to determine if cyclosporin could be used in the treatment of atopic dermatitis (AD) in dogs. Thirty dogs with AD were randomly assigned to receive a once daily oral solution for 6 weeks of either cyclosporin 5 mg kg−1 or prednisolone 0.5 mg kg−1. Both investigators and owners were blinded to treatment. Skin lesions were graded at the start of the study and at weeks 3 and 6. The investigators used the Canine AD Extent and Severity Index (CADESI). Owners assessed pruritus using a Visual Analog Scale (PVAS). In both groups, CADESI and PVAS values were significantly lower at 6 weeks post-treatment than before the initiation of therapy (Friedman test, P < 0.0004). The percentage reductions in CADESI and PVAS values were not significantly different between the groups (Mann–Whitney test, P > 0.3) (Table). Three dogs did not complete the study. One dog treated with prednisolone developed a superficial pyoderma. In the cyclosporin group, one dog developed angioedema after 2 days of treatment and in another dog the drug may have worsened pre-existing regurgitation. We found that in dogs with AD, the effect of cyclosporin was similar to that of prednisolone. We propose that cyclosporin could be considered as an alternative to corticosteroid therapy in atopic dogs. The Neoral® cyclosporin for this study was provided by Sandoz-Pharma.
See table 1.
Electron microscopic observations of the stratum corneum intercellular lipids in normal and atopic dogs
T. OLIVRY, A. O. INMAN, S. M. DUNSTON, N. A. MONTEIRO-RIVIERE and H. GATTO
College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA; Virbac SA, Carros, France
Human patients with atopic dermatitis commonly exhibit dry skin because of excessive transepidermal water loss. Increased water evaporation may be caused by inadequate secretion of sphingolipids following an abnormal extrusion of lamellar bodies. The present study was performed to determine whether abnormalities in stratum corneum lipids could be observed in the skin of atopic dogs. Skin punch biopsy specimens were obtained from clinically normal skin of five atopic and five normal dogs. Samples were fixed in Trump’s fixative and postfixed with ruthenium tetroxide (RuO4), thus allowing an appropriate fixation of lipids. Electron photomicrographs were obtained from the lower and mid-stratum corneum and examined in a blinded fashion. The extent and intensity of intercellular lipid lamellae were graded semiquantitatively on a 5 point linear scale. Both extent and intensity scores were significantly lower in nonlesional atopic than normal control canine skin (Table) (P < 0.001, Mann–Whitney test). In general, intercellular lipid deposits in atopic skin were more heterogeneous than in normal control skin and exhibited structural anomalies. The results of the present study suggest that the epidermal lipid barrier is defective in atopic canine skin. Additional studies are needed to further characterize the biochemical defect and to correct it with nutritional and/or pharmacological agents. Virbac SA, FRANCE funded this study.
A placebo-controlled blinded trial of misoprostol monotherapy for canine atopic dermatitis: effects on dermal cellularity and cutaneous tumor necrosis factor-α gene transcription
T. OLIVRY, C. RIVIERRE, H. A. JACKSON, K. M. MURPHY, E. PETERS, S. M. DUNSTON, and G. A. DEAN
College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
In a previous open study, misoprostol monotherapy was shown to decrease clinical signs of canine atopic dermatitis (AD). The current study, using a blinded placebo-controlled design, was performed to confirm earlier results and to determine whether the efficacy of misoprostol was due to decreased dermal cellularity and TNF-α gene transcription. Twenty dogs with AD were given 3 weeks of either placebo or misoprostol (5 μg kg−1 orally three times daily). Investigators graded skin lesions using the Canine AD Extent and Severity Index before and after treatment. Owners assessed pruritus using a Visual Analog Scale (VAS). Skin biopsies were obtained from lesional skin at similar sites before and after therapy. Specimens were processed for histopathology, and dermal cell counts were estimated using a VAS. Messenger RNA was extracted from frozen sections of each sample and the number of skin TNF-α mRNA copies was obtained from a quantitative-competitive RT-PCR using canine-specific primers. Both pruritus and clinical scores were significantly decreased after misoprostol therapy but not after placebo administration. During misoprostol therapy, the median decrease in pruritus and clinical scores was approximately 30%. Both dermal cellularity and number of cutaneous TNF-α mRNA copies were lower in biopsies from dogs receiving misoprostol but were not significantly different from those of placebo-treated animals. These observations confirm the modest efficacy of misoprostol for treatment of canine AD and suggest that the effects of misoprostol are not due to an inhibition of inflammatory cell emigration nor to transcription of TNF-α gene. This study was funded by a grant from Searle.
Effects of steroidal and nonsteroidal antiphlogistic drugs on eicosanoid synthesis in the skin: studies with the isolated perfused bovine udder
W. BÄUMER and M. KIETZMANN
Institute for Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine, Hannover, Germany
Using isolated perfused bovine udder as an in vitro model for dermal inflammation, the effects of topically administered arachidonic acid (AA) on prostaglandin and leukotriene synthesis in skin were studied. Within 1 h after cattle slaughter, the udder was perfused with a gassed tyrode solution and a topical ointment containing AA (3 mg cm−2 skin) was applied. Skin biopsies were taken from treated and untreated areas at 15, 60, 120 and 180 min after treatment. Using enzyme immunoassays, prostaglandin E2 (PGE2) and peptido-leukotrienes (LTC4/D4/E4) were measured in the skin. Following this, the effects of indomethacin and clobetasol-17-propionate (administered topically) as well as flunixin meglumate and meloxicam (administered via the perfusion fluid) were studied. Compared to controls, AA caused a significant increase in dermal PGE2 and LTC4/D4/E4 concentrations. Treatment with indomethacin (1.6 mg cm−2) and clobetasol-17-propionate (90 μg cm−2) administered 60 min before AA administration diminished the inflammatory reaction. Flunixin meglumine (1 μg mL−1) was administered 30 min after, and meloxicam (3 μg mL−1) was administered 60 min before AA application. Three hours after AA administration, a significant inhibition of PGE2 synthesis was induced by flunixin. In contrast, meloxicam showed only a slight effect. The effect of flunixin is comparable to in vivo results. It is known from animal studies that the anti-inflammatory effects of meloxicam are evident within 6 h after treatment. Therefore, the incomplete effect of meloxicam may be due to pharmacokinetics. In conclusion, the described in vitro model seems suitable for studies of pharmacological effects on eicosanoid synthesis in the skin.
Reflection spectroscopy as a non-invasive method for determination of substances: experiments on the pharmacokinetics of β-carotene in the skin
F. NIEDORF, M. KIETZMANN and H. JUNGMANN
Institute for Pharmacology, Toxicology and Pharmacology, School of Veterinary Medicine, Hannover, Germany
Using β-carotene as a test compound, reflection spectroscopy was evaluated as a noninvasive method for taking skin measurements. A study on the pharmocokinetics of β-carotene distribution in the skin was done using the isolated perfused bovine udder model. Within 1 h after cattle slaughter, the udder was perfused with a gassed tyrode solution containing different β-carotene concentrations. Distribution in the skin was followed by noninvasive reflection spectroscopy. In this study, six skin areas on each udder were measured at 20-min intervals for up to 5 h. A significant increase in dermal β-carotene concentrations was observed using concentrations of 20 μg mL−1 of perfusion fluid. A steady state was reached within 150 min. Concentrations of 2 μg mL−1 of perfusion fluid resulted in only a marginal increase in β-carotene concentrations within 5 h. Perfusion with tyrode without β-carotene resulted in no increase in basal β-carotene concentrations. A correlation with β-carotene concentrations measured by HPLC from skin biopsy punches was confirmed. Additionally, a decrease of the β-carotene concentrations was demonstrated after UV-irradiation of the skin. In conclusion, the reflection-spectroscopy is a suitable method for quantitative noninvasive determination of compounds in the skin.
House contamination due to Microsporum canis infected cats and dogs
M. CORAZZA, F. MANCIANTI and P. D’ACHILLE
Universita degli studi di Pisa, Pisa, Italy
Environmental contamination of homes by dogs and cats infected with Microsporum canis is described. Dermatophytosis was diagnosed in 19 animals (14 cats and five dogs) living in 19 different homes. Collectively, these animals were in contact with 61 people and 32 other animals. Of the 14 cats, 12 were symptomatic and two were asymptomatic (10 DHS and four Persian). All dogs were symptomatic. After diagnosis, patients were treated for 9 weeks. All cohabiting people and pets were screened for M. canis. Using contact plates the floors, carpets and upholstered furniture and places not directly contaminated by the infected animal were sampled three times. Owners were instructed to clean their homes with vacuuming and a commercial detergent. Ten of 14 cats and all dogs were cured at the end of the study. Tinea corporis due to M. canis was found in 6/61 people living with cats (four different houses). Nine of 23 animals cohabiting with cats (four houses) and 2/9 animals cohabiting with dogs (two houses) were culture positive. Initial cultures of the home revealed M. canis contamination in 17/19 houses. Two houses were culture negative (one symptomatic cat, one dog). At the second and third sampling, houses with dogs were culture negative. At the second and third sampling, nine and four houses with cats were culture positive, respectively. At the first sampling, M. canis was isolated from 84% of floors, 58% of carpets and upholstered furniture, and 31% of inaccessible areas. Supported by grant from MURST.
Demodicosis in a red-handed tamarin monkey (Saguinus midas midas) familial group: successful treatment with amitraz
B. POLACK, L. FIETTE, J. GUILLOT, F. TOUATI, M. DEVILLE and T. PETIT
Unité de Parasitologie-Mycologie-Dermatologie, Ecole Nationale Vétérinaire d’Alfort; Maisons-Alfort Cedex; Unité d’Histo-Pathologie, Institut Pasteur, Paris; Zoo de La Palmyre, Les Mathes, France
This report describes the successful treatment of demodicosis using amitraz in a family of five red-handed tamarins (Saguinus midas midas) monkeys. The family group consisted of an adult female and her four offspring (two male, two female). Skin lesions were present in all five animals, but were first seen in a young male. An erythematous, elevated 1 cm plaque was seen on the forehead, and initially diagnosed as a haematoma. During the following year, lesions progressed and the animal was anaesthetized for diagnostic testing. Alopecic nodules were present on the forehead and cheeks and several erythematous and hyperpigmented alopecic plaques (< 1 cm), with follicular casts, were found on the trunk, arms and thighs. Skin scrapings of the lesions showed numerous Demodex mites that did not match any previously described species. Demodicosis was found on skin biopsy of lesions from the forehead and forearms. The four other monkeys in this family group were examined 2 months later and similar, but smaller, lesions were seen on the body and face (n = 1 monkey). Monkeys were treated weekly with topical amitraz after being anaesthetized. Facial lesions were treated with a 0.5% amitraz solution in 50% propylene glycol and 50% water; the solution was dabbed on the skin with a cotton-tipped swab. A 0.05% amitraz solution in water was applied to lesions on the body using a toothbrush. Two months after the end of the treatment, mild lesions were found in only one monkey, the monkey that had been most severely affected. One year later, lesions had resolved in all five monkeys. Demodicosis has been described in monkeys previously, but successful treatment with amitraz has never been reported.
Adult-onset demodicosis in dogs: a retrospective study of 28 cases
C. RENVIER and J. GUILLOT
Unité de Parasitologie-Mycologie-Dermatologie, École Nationale Vétérinaire d’Alfort, Maisons-Alfort, France
The pathogenesis of adult-onset canine demodicosis is poorly understood. This disease has been reported in association with endocrine and other internal diseases and as a result of corticosteroid or chemotherapy administration. In this retrospective study, we describe 28 adult dogs with adult onset-demodicosis. These cases were identified from a search of the medical records of dogs presented to the Veterinary College of Maisons-Alfort between 1994 and 1998. Age at time of presentation ranged from 2 to 16 years. Demodicosis was diagnosed via compatible clinical signs and by skin scrapings (> 5 Demodex mites per field). In seven dogs (25%), more than one major body region was affected (i.e. generalized demodicosis). Pododemodicosis was seen in five dogs (18%). Eighteen dogs (64%) had pustular skin lesions and 10 (36%) had scaling lesions. Predisposing factors were identified in 16 animals (57%). Chronic administration of corticosteroid therapy was most the most common cause (six dogs). Other underlying causes included hypothyroidism (four dogs), neoplastic diseases (three dogs), autoimmune diseases (two dogs) and contact hypersensitivity (one dog). At the time of diagnosis, an underlying cause was not found in 12/28 dogs. Long-term follow-up was not possible in many cases and may account for this.
Malassezia otitis and dermatitis in two cryptorchid dogs
G. MARIGNAC, B. POLACK, F. GARNIER and L. BOULOUHA
Unité de Parasitologie, Mycologie et Dermatologie, École Nationale Vétérinaire d’Alfort, Maisons-Alfort; Service de Biochimie, École Nationale Vétérinaire de Lyon, Marcy l’Éoile; Service d’Anatomo-pathologie, École Nationale Vétérinaire d’Alfort, Maisons-Alfort, France
Two male cryptorchid dogs, a 4-year-old German shepherd (GS) and an 11-year-old Bauceron (B), were presented for the complaints of generalized pruritus and hair loss of 2–24 months’ duration. Both dogs had gynaecomastia with pruritus, erythema, lichenification and oily seborrhoea on the ventral abdomen and axillae. In addition, subcutaneous nodules were palpable lateral to the penile sheath. The German shepherd dog had bilateral erythematous ceruminous otitis externa. Several alopecic plaques were observed on the trunk of the Bauceron dog. Hair trichograms showed predominantly telogen hairs. Skin scrapings were negative and Malassezia spp. were found on cytological smears from the ears and/or skin. Fungal culture from the Bauceron dog showed numerous colonies of Malassezia pachydermatis. In addition, a complete blood count from this dog showed a mild nonregenerative anaemia. Hormonal analyses revealed hyperoestrogenaemia in both dogs and both dogs were castrated. Histopathological examination of the testicles revealed a seminoma (GS) and a Sertoli cell tumour (B), respectively. Econazole shampoo, antibiotics and/or otic treatment resolved the skin lesions with no recurrence of skin or ear lesions in either of the dogs. Seborrhoeic skin disorders are reported in dogs with hormonal imbalances, particularly in dogs with hypothyroidism and sex hormone disorders. As M. pachydermatis proliferation is often associated with seborrhea, dogs with these disorders may have secondary yeast infections. Abnormal sex hormones concentrations and testicular abnormalities were found in both of these dogs. In both dogs, castration resulted in an apparent cure of the chronic Malassezia dermatitis.
The effects of corticosteroid treatment on anti-flea saliva IgE, as measured by intradermal skin test and ELISA, in laboratory beagles with experimentally induced flea allergy dermatitis
K. B. CLARKE, D. E. BEVIER, S. V. RADECKI and C. A. MCCALL
Heska Corporation, Fort Collins, Colorado; Purdue University, College of Veterinary Medicine, West Lafayette, Indiana, USA
Corticosteroids (CS) are widely used for the treatment of atopic dermatitis and flea allergy dermatitis (FAD) in dogs. CS are reported to suppress intradermal skin test (IDST) reactions but the effect of these drugs on allergen-specific serum IgE concentrations is less well documented. Eight laboratory beagles previously sensitized to fleas by intermittent flea bites and flea infestation were used to investigate the effects of CS on IDST and serum IgE concentrations. Dogs were exposed to fleas and symptoms compatible with FAD developed. The dogs were treated twice with methylprednisolone acetate (2 mg kg−1 subcutaneously) at 4 week intervals. Control dogs were not treated. Intradermal skin testing with proprietary flea salivary allergens (FSA) was performed at the beginning of the study and 4 weeks after the second CS treatment. Blood for serum IgE testing was drawn just prior to each intradermal testing. This CS regimen did not completely suppress immediate IDST reactions to FSA, although the size of the wheals tended to be smaller and their appearance was altered in the treatment group. Serum IgE specific for FSA, as measured by FcεR1α-based ELISA, was also readily detectable in both control and CS treated animals. The 8-week CS treatment regimen used in this study does not preclude the use of either intradermal testing or FcεR1α-based ELISA for the detection of anti-FSA IgE in dogs with FAD.
Susceptibility testing of Malassezia pachydermatis using a urea broth microdilution assay
T. MURAI, Y. NAKAMURA, S. WATANABE and A. HASEGAWA
Kinder-Care Veterinary Clinic, Tochigi; Teikyo University School of Medicine, Tokyo; Nihon University School of Veterinary Medicine, Kanagawa, Japan
The in vitro susceptibility of six isolates of Malassezia pachydermatis to antifungal drugs was determined by a urea broth microdilution method. Six isolates were obtained from the ear canal of dogs and cats. In this assay, urease activity was measured instead of organism viability (i.e. colony development). The urease activity of the strains was measured by colour changes in optical density at 545 nm. The end point in this assay was a 99% inhibitory concentration. In this assay the mean minimum-inhibitory concentration (MIC) of bifonazole, itraconazole, amorolfine and terbinafine were 3.2 μg mL−1, 1.6 μg mL−1, 25 μg mL−1 and 3.2 μg mL−1, respectively. MIC values were slightly higher with this assay than those obtained by checking for colony development on Dixon agar plates. There were no significant differences in the MICs between the isolates. This assay may be useful in selecting appropriate drugs for the treatment of refractory M. pachydermatis otitis and dermatitis in dogs and cats.
In vitro antimicrobial activity of Hexadene® Flush with Spherulites™ and Resichlor® with Spherulites™ against Staphylococcus intermedius, Pseudomonas aeruginosa, and Malassezia pachydermatis
O. OKWUMABUA, F. GOODMAN and O. ELFASSY
School of Veterinary Medicine, Tuskegee University; Virbac AH, Inc., USA
In dogs, cutaneous infections with Staphylococcus intermedius, Pseudomonas aeruginosa, and Malassezia pachydermatis are common. A recent study reported that the formulation of a shampoo, and not just the concentration of antimicrobial, play a role in efficacy against these organisms. This study evaluated the in vitro activity of Hexadene® Flush with Spherulites™ (0.25% chlorhexidine gluconate), Resichlor® with Spherulites™ (2% chlorhexidine gluconate), and a cleansing solution against these organisms. Bacterial isolates were obtained from patients in a referral practice. Organisms were grown to log phase, diluted to a concentration equivalent to 107 cfu mL−1, and exposed to a 1:1 or 1:5 dilution of Hexadene® Flush with Spherulites™ and the cleansing solution or a 1:5 or 1:25 dilution of Resichlor® with Spherulites™. Aliquots were removed after 1, 2, 4, 8, 16, and 30-min of contact time, spread-plated and incubated for colony counts. At both dilutions, Hexadene® Flush with Spherulites™ eliminated all three bacteria at the 1-min contact time. A dilution of 1:5 Resichlor® with Spherulites™ was effective against all three organisms at all contact times. At a 1:25 dilution, S. intermedius was eliminated after a 2-min contact time. Pseudomonasaeruginosa and M. pachydermatis were eliminated after a 1-min contact time. At a 1:1 dilution, the cleansing solution eliminated S. intermedius after 8 min, P. aeruginosa after 16 min and M. pachydermatous after 30-min contact time. Greater than 3000 CFU mL−1 were counted after 30-min contact time at the 1:5 dilution. In conclusion, these in vitro data show that Hexadene® and Resichlor® products have efficacy against three common skin pathogens and may be useful in the clinical management of skin diseases associated with these organisms.
A case of congenital lymphoedema in a cross-breed collie dog
A. VERCELLI and L. DEL VECCHIO
Ambulatorio Veterinario Associato, Torino, Italy
Congenital lymphoedema is very rare in both people and animals. It is characterized by oedema of the limbs that can be complicated by secondary infection and fibrosis. Congenital lymphoedema has been described in several different dog breeds. We describe a case of bilateral oedema of the hindlegs of a 10-month-old, female mixed breed collie dog. Except for the lymphoedema, there were no other physical abnormalities found. Prior to examination, several different courses of therapy, including diuretics and glucocorticoids, were tried with no success. In order to differentiate between primary congenital lymphoedema and the acquired form, the following diagnostic tests were performed: blood profiles, cardiac echogram, cardiac echoDoppler, abdominal radiographs and lymphography. In addition, skin biopsies were taken and routinely processed for histopathology. Samples were stained with haematoxylin and eosin and an immunohistochemistry study with vimentin was performed to evaluate lymphatic vessels. The biopsies revealed marked oedema and prominently dilated lymphatic vessels that were positive for vimentin. The physical examination, the diagnostic evaluation and histological studies confirmed the clinical diagnosis of congenital lymphoedema. The dog’s legs were wrapped with bandages as this reduced the lymphedema for several hours. An oral treatment with 3 g of rutin (Venoruton®) once daily was attempted. The dog was followed for 12 months and no surgical treatment was needed.
Assessment of 17-hydroxyprogesterone (OHPG) response to ACTH stimulation in healthy dogs and in dogs with hypercorticism
B. LILIART, L. MARTIN and F. STAMBOULI
Ecole Vétérinaire, Nantes, France
The hormone, 17-OHPG, has been proposed as a possible marker of abnormal steroid synthesis in either the gonads or the adrenals. Abnormal steroid synthesis is believed to be associated with such conditions as tumours, polycystic ovaries, pre-Cushings syndrome, seasonal flank alopecia, and ‘alopecia X’. The purpose of this study was to determine the normal ranges of 17-OHPG in the dog. Because the secretion is probably pulsate in nature we used the ACTH stimulation test in this study. Seventy-four dogs (43 male, 31 female) between the ages of 1 and 14 years of age were used as a normal population. One hundred and three dogs with endogenous hyperadrenocorticism as diagnosed by ACTH stimulation test (cortisol > 450 n m L−1) were also used. Dogs were given 0.25 mg of ACTH (Synacthene®) intramuscularly and samples collected at 0 and 90 min post-ACTH. Cortisol concentrations were measured via radioimmunoassay. In healthy males and anestrus females there was no correlation between basal 17-OHPG (mean, 1.6 n m L−1, SD = 1.2) and post-ACTH stimulation values (mean = 5.4 n m L−1, SD = 2.8) and no correlations between basal or post-ACTH values for 17-OHPG progesterone and cortisol. In dogs with hypercortisolism, 17-OHPG concentrations were increased and correlated with increased cortisol concentrations (P < 0.001) (basal: mean = 1.9 n m L−1, SD = 2.5, post-ACTH: mean = 12.2 n m L−1, SD = 8.3). Basal concentrations of 17-OHPG were below 4 n m L−1 and 11 n m L−1 after ACTH. In dogs with hyperadrenocorticism, the secretion of 17-OHPG was increased and correlated with the increased cortisol concentrations.
Equine hirsutism: a retrospective study of 19 cases (1990–2000)
B. LILIART, L. MARTIN and F. STAMBOULI
Ecole Vétérinaire, Nantes, France
The most common cause of equine hirsutism is hyper-adrenocorticism; however, it can also be associated with hyperinsulinaemia. The exact pathogenesis of the abnormal hair growth is not known. In this study, we reviewed the records of 19 horses diagnosed with equine hirsutism. The horses were of various breeds. There were nine males and 12 females ranging in age from 14 to 25 years of age. ACTH stimulation tests were done using intravenous ACTH (Synacthene®). Serum samples were collected at 0 and 90 min post-ACTH administration and cortisol concentrations were determined by radioimmunoassay (RIA). Insulin and IGF1 concentrations were also measured via RIA. Thyroid function test was evaluated via TSH stimulation test using 40 UI of bovine TSH IV. Thyroid hormones were measured via RIA in 0 and 5 h post-TSH serum samples. Hypercortisolism was apparent in only four horses. Two horses had received high doses of corticosteroids. Sixteen horses showed hyperinsulinaemia (mean 129 μUI mL−1) with only a slight increase in glucose (mean 240 mg dL−1). More horses than expected had low thyroid function. All of the horses tested for IGF1 had increased values above the laboratory normal range but also had normal cortisol and thyroxine concentrations. Two horses with elevated IGF1 values were treated with quinagolide. Their IGF1 values decreased along with their insulin values indicating a positive response to therapy. All horses in this study had clinical hirsutism but only nine had hyperadrenocorticism. The findings in this study appear to suggest a role for insulin, GH, or IGF1 in the pathogenesis.
Comparative study between cytology and histopathology in the diagnosis of canine neoplasms
A. M. DE MAGALHÃES, R. R. RAMADINHA, P. V. PEIXOTO and C. S. L. DE BARROS
Universidade Federal Rural do Rio de Janeiro; Universidade Federal de Santa Maria, Brazil
In this study, we compared the accuracy between the cytological and histological diagnosis of 150 canine skin tumours. Several stains were used for cytological examination of specimens including Wright’s, May-Grünwald-Giemsa, new methylene blue and Papanicolau (exceptional staining of nuclear morphology). Stains for histological examination of biopsies included haematoxylin and eosin, van Gieson’s, Sudan black B, Toluidine blue and Periodic acid-Schiff. When the histological diagnosis was considered the accurate parameter, the cytological diagnosis was correct in 85.3% of cases. Histological examination was able to determine the embryonic origin of neoplasms in 4.0% of cases and the prognosis in 1.3%. In 9.3% of cases, the cytological diagnosis differed from the histological diagnosis. In two cases (1.3%), a reexamination revealed that the cytological diagnosis was correct, increasing the accuracy of cytological diagnosis to 86.6% in this study. The best technique for obtaining cytology specimens was fine needle aspirate. Cytology was unsuitable for the diagnosis of mammary neoplasms due to the wide variation of cytological specimens obtained from different sites of the same tumour. Routine impression smears are not recommended for the evaluation of mesenchymal tumours because inadequate samples are obtained. We recommend making exfoliative cytological preparations via gentle scrapings of the tissue. The Wright’s stain proved to be best stain for cytological examination of specimens. New methylene blue for mastocytomas, van Gieson for leiomyomas and leiomyosarcomas, Sudan black B for lipomas and liposarcomas and Toluidine blue for mastocytomas were especially useful in visualizing the fine morphological details of various epithelial and mesenchymal tumours in this study.
Canine otitis externa: evaluation of clinical classificatiion using cytology and bacteriology
J. H. BECK and W. OSTHOLD
Grevenbroich; Tieraerztliche Klinik am Boekelberg, Moenchengladbach, Germany
Otitis externa clinically may be classified as erythematous, ceruminous, erythematous and ceruminous, or purulent. In clinical practice, it is widely assumed that otitis externa is associated with a microbial infection. The purpose of this study was to evaluate and compare the cytological and bacterial findings in 84 cases of otitis externa. Specimens were collected with a swab and cytological specimens were stained using Diff-Quick and Gram stains. Sterile swabs were used to collect bacterial cultures and these were done at a commercial laboratory. On cytology, > 5 yeast and > 5 bacteria per HPF were considered compatible with a microbial infection. On culture, moderate (++) and high numbers (+++) of bacteria were considered compatible with an infection. The results are listed in the table below.
see Table 3.
In all cases of purulent otitis externa, cytological and bacterial findings correlated. However, in the other cases of otitis externa correlation was more variable and results should be interpreted with caution, as all cases may not require antimicrobial therapy.
Concurrent cutaneous and systemic amyloidosis in a Siberian husky dog
E. GUAGUÈRE, F. DEGORCE RUBIALES, A. POUJADE and J. P. MAGNOL
Clinique Vétérinaire Saint Bernard, Lomme, France
LAPVSO, Toulouse; Unité de Cancérologie et de, ENVL Marcy l’Etoile, France
The purpose of this report is to describe a case of concurrent cutaneous and systemic amyloidosis in a dog. A 5-year-old female Siberian husky dog was referred for the complaint of cutaneous lesions on the trunk. These lesions were characterized by dermal papules, purpuric macules, ulcers covered with bleeding crusts, and dermatosparaxis that subsequently revealed an orange yellow-coloured dermis. Histological examination of a skin biopsy showed a diffuse deposition of an amorphous eosinophilic material in the dermis along with fibroplasia, angiomatosis, and haemorrhage. When sections were examined with a polarized light, a green birefringence, characteristic of an amyloid substance, was seen. Serum protein electrophoresis revealed a slight increase in β and γ protein fractions. No other haematological, biochemical or urinary abnormalities were found. For about 1 year, the cutaneous lesions were static. Shortly thereafter, the dog developed kidney failure. Kidney biopsy confirmed the presence of renal amyloidosis and chronic interstitial nephritis. Serum protein electrophoresis revealed a decrease in the albumin fraction and an increase in the γ-2 and β fractions. In addition to these abnormalities, the dog had marked proteinuria and increased serum concentrations of urea and creatinine. The dog developed hypercoaguable syndrome and died from pulmonary thrombo-embolism. The death of the sire of this dog from renal amyloidosis suggests a genetic predisposition.
Genetic follicular dysplasia in Pont Audemer spaniel dogs: a report of eight cases
E. GUAGUÈRE, F. DEGORCE-RUBIALES, A. POUJADE, J. LECANU, M. PETRIOWSKI and P. PRÉLAUD
Clinique Vétérinaire Saint Bernard, Lomme; LAPVSO, Toulouse; CERI, Paris, France
Genetic follicular dysplasia (GFD) has been reported in several breeds of dogs. The purpose of this report is to describe the clinical and histopathological findings of eight cases of GFD in the Pont Audemer spaniel dog. Follicular dysplasia was recognized in eight Pont Audemer spaniel (two males and six females) dogs. The individuals ranged in age from 1 to 3 years. Non-inflammatory areas of alopecia limited to the brown haired areas of the trunk and ears developed between 7 and 18 months of age. Histological examination of skin biopsy specimens revealed primary and secondary hair follicles with moderate to marked orthokeratotic hyperkeratosis and follicular dilatation leading to ‘dwarf feet figures’. The follicular infundibulum showed hypergranulosis and a thickened stratum corneum composed of compact keratin. The base of infundibulum was irregular, distorted and often acanthotic. Clumped melanin pigment was often seen free within the follicular infundibulum near narrow hair shafts. It was infrequently seen within hair shafts. Pigment clumping was rare in the outer root sheath of the hair follicle. There was mild to moderate vacuolar alteration in the inner root sheath, and sometimes in the outer root sheath of anagen hair follicles. The inner root sheath had large amounts of trichohyalin granules. Numerous apoptotic cells were found in the outer root sheath of either anagen or telogen hair follicles. Endocrine tests were within laboratory normals. In two cases, there was a spontaneous but transient regrowth of hair. Melanin implant therapy was tried in two cases with no response. An analysis of the dogs’ pedigrees confirmed a recessive autosomal trait with variable penetrance. This report confirms the existence of GFD in the Pont Audemer spaniel dogs.
Cell proliferation as a diagnostic tool to distinguish well-differentiated canine squamous cell carcinoma from infundibular keratinizing acanthoma
L. DELLA SALDA, R. PREZIOSI, M. MAZZONI and P. S. MARCATO
University of Teramo and University of Bologna, Italy
It can be difficult to distinguish between well-differentiated canine squamous cell carcinoma (WDSCC) and infundibular-keratinizing acanthoma (keratoacanthoma) based the microscopic examination alone. This is problematic for pathologists, especially when small biopsy specimens are submitted, making it difficult to recognize the typical ‘cup-shaped’ histological pattern of the infundibular keratinizing acanthoma (IKA). The purpose of this study was to investigate the use of cell proliferation in WDSCC and IKA as an aid in differentiating these two skin tumours. Eighteen IKA and 10 WDSCC were selected for this study. Two different methods to assess cell proliferative activity in situ were tested: MIB1 immunohistochemical detection and AgNOR proteins silver staining. Quantification of the proliferative parameters (AgNOR proteins content and MIB1 nuclear positivity) was performed by means of an image analyser and expressed as MIB1 index and AgNOR area (MNORA). Both MIB1 immunohistochemical and AgNOR histochemical patterns were different in WDSCC and IKA; moreover analysis of variance showed a significant difference for both parameters employed (MIB1 index, MNORA) between WDSCC and IKA (P < 0.003 for MIB1 index; P < 0.0001 for AgNOR area). A positive correlation was seen in linear regression analysis between MIB1 index and AgNOR area (P < 0.0002; R = 0.74). These results show that canine WDSCC and IKA have different proliferative behaviours and that assessment of proliferative activity can be used as an adjuvant diagnostic aid for differentiating these two tumours.
Canine and feline scabies in Brazil (São Paulo): clinical and epidemiological aspects
C. E. LARSSON, M. OTSUKA, L. E. B. LUCARTS, R. C. C. CASTRO, E. H. DELAYATE, A. C. BALDA and P. M. L. GERMANO
Serviço de Dermatologia do Departamento de Clínica Médica da Faculdade de Medicina Veterinária e Zootecnia e Departamento de Prática de Saúde Pública da Faculdade de Saúde Pública da Universidade de São Paulo, Brazil
At the Veterinary Teaching Hospital (HOVET) in FMVZ/USP, sarcoptes and notoedric mange are the second and third most commonly diagnosed parasitic skin diseases, respectively. In São Paulo, animal to human transmission of scabies has been reported to occur in 12%–40% of cases. Between 1984 and 1999, 2527 cases of canine and feline scabies were diagnosed at HOVET, or approximately 13 cases per month. Canine scabies (1985) and feline scabies (542) represented 6.8% and 15.7%, respectively, of the cases seen. Feline scabies was more frequent than canine scabies (P < 0.01). Canine scabies was more prevalent in pure bred dogs (57.5%) with long hair (77%) and the most commonly affected dog breeds were poodles (20.4%), German shepherds (17.4%), and cocker spaniels (17.2%). Canine scabies was more frequent in males (53.5%) and 48% of the cases occurred in male dogs < 12 months old. Approximately 77.2% of the dogs were infested in the first 3 years of life. Stray cats (77.5%), short-haired cats (82.8%), and male cats (58%) were most commonly affected. Feline scabies was most common in the Siamese (82.8%), Persian (14.8%) and Burmese (1.6%) cat breeds. For notoedric mange, 47% and 80.5% of cats were < 3 years and < 1 years of age, respectively. There was no seasonal difference in the occurrence of scabies in either cats or dogs when results were analysed by anova test (P = 0.05).
Antimicrobial activity in vitro of shampoos containing chlorhexidine and miconazole combined, and chlorhexidine alone
D. H. LLOYD and A. I. LAMPORT
Royal Veterinary College, University of London, Hawkshead Campus, North Mymms, UK
Chlorhexidine and miconazole are used in the topical treatment of canine skin infections. This study aimed to determine in vitro the relative activity of a 2% chlorhexidine and 2% miconazole shampoo (Malaseb®, Leo Animal Health, UK) and a 3% chlorhexidine shampoo (Pyoderm®/Hexadene®, Virbac, France/US) against five canine clinical isolates each of Staphylococcus intermedius and Malassezia pachydermatis. Log phase cultures were suspended, at concentrations of 103–5 colony forming units (cfu) per ml, in 1/25 dilutions in saline of the shampoos or in saline only (controls), and held at ≈21°C. Aliquots were removed at intervals of 2, 4, 8, 16 and 30 min, spread-plated on blood agar or modified Dixons agar (for Malassezia) and counted after incubation for 48 h (Staphylococcus) or 72 h (Malassezia). The staphylococci failed to survive for 2 min with either of the shampoos; control suspensions remained at 1.4×104 cfu mL−1 throughout the 30-min period. With Malassezia, mean counts of 146 and 6, and 126 and 6 cfu mL−1 were obtained at 2 and 4 min, respectively, with Malaseb and Pyoderm/Hexadene. No Malassezia organisms survived 8 min exposure. Control suspensions remained at 3×103 cfu mL−1 throughout. This study demonstrates that the 3% chlorhexidine shampoo is equivalent in activity, in vitro, to the 2% chlorhexidine and 2% miconazole shampoo. Even when diluted 1/25, both have microbicidal activity against both S. intermedius and M. pachydermatis within a period of exposure likely to be achieved during routine use in vivo. This study was sponsored by Virbac, France.
The effect of zileuton on sulfido-leukotriene production from peripheral leukocytes and skin in house dust mite positive atopic dogs
D. W. CROW, R. MARSELLA and C. F. NICKLIN
College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
Leukotrienes (LT) have been suggested to play an important role in atopic dermatitis in both people and dogs. Zileuton inhibits 5-lipoxygenase, preventing production of sulfido-LT (s-LT) and also LTB4. This prospective, double-blinded placebo-controlled pilot study included nine dogs with documented atopic dermatitis and a positive intradermal skin test to house dust mite (HDM). Three dogs were given placebo and six were given zileuton at a dose of 2 mg kg−1 PO TID for 4 weeks. Peripheral blood samples and skin biopsies were collected. Sulfido-LT synthesis from peripheral leukocytes was measured after stimulation with lipopolysaccharide (LPS), HDM and monoclonal antibody to high affinity human IgE receptor and no statistically significant difference was found between zileuton and placebo treated dogs. All dogs received intradermal injections of histamine, saline, HDM, and LPS. Sulfido-LT concentrations in skin samples harvested 90 min post-intradermal injection from stimulated (HDM and LPS) and unstimulated sites (saline) were measured and no statistically significant difference was detected between zileuton- or placebo-treated dogs. These results suggest that zileuton did not alter s-LT synthesis from skin or peripheral leukocytes in this small number of atopic dogs. Supported by a grant from the University of Florida.
Pollen allergies in atopic dogs in France
In France, allergy to house dust mite is reported to be one of the most common cause of atopic dermatitis in dogs. However, the importance of pollens in allergic skin disease is underestimated. In this study, the importance of pollen allergy as a cause of atopic dermatitis is reported. Three hundred and eighty-four dogs were intradermally skin tested over 5 years using 44 aeroallergens, including 28 seasonal pollens. Pollen allergens were considered important allergens in 44% (n = 169) of dogs. Eleven dogs received immunotherapy (IT) to only pollen allergens and the remaining dogs received IT for seasonal and nonseasonal allergens. The two most common pollens causing reactions were false acacia (Robinia pseudoacacia) in 55 dogs (32.5%) and dandelion (Taraxacum vulgare) in 52 dogs (31%). Then other pollens involved included ragweed (48 dogs), Salicaceae trees (45 dogs), Betulaceae trees (37 dogs), mugwort (36 dogs), grasses (33 dogs), lime-tree (33 dogs), Fagaceae trees (33 dogs) and ox-eye daisy (32 dogs). Other trees and weeds were of less importance. Seventy-five dogs sensitized to both seasonal and nonseasonal allergens had positive reactions to only pollen. Of these dogs, 26 were sensitized to dandelion and 16 to false acacia (56%). Dandelion, false acacia, lime and ox-eye daisies are prevalent entomophilous species leading to allergies because of dogs’ close proximity to these plants. Because of their horizontal position and their behaviour, dogs are in direct contact in the environment with allergenic proteins. The Compositae, first weed family was especially important in our study. Due to the high percentage of dogs with pollinosis (44%), hyposensitization therapy is indicated.
Treatment of a Microsporum canis infection in a colony of Persian cats with griseofulvin and a shampoo containing 2% miconazole, 2% chlorhexidine, 2% miconazole and chlorhexidine or placebo
K. V. MASON, A. FROST, D. O’BOYLE and M. D. CONNOLE
Dermcare-Vet Pty Ltd, Springwood, Queensland, Australia
School of Veterinary Science, University of Queensland, Australia
The treatment of Persian cats with Microsporum canis and the elimination of infective spores from the environment are difficult tasks. Systemic griseofulvin is slow to sterilize the coat, which is the source of infective spores. Topical adjuvant therapy could potentially reduce the time to clinical cure and minimize, or prevent, environmental contamination. This trial describes the use of four topical shampoos as adjunct therapy in a cattery of Persian cats being treated with griseofulvin. All cats received griseofulvin orally once daily and were bathed twice a week. All cats were assessed on weeks 0, 3, 5, and 9 by scoring Wood’s lamp fluorescence and by dermatophtye cultures obtained via McKenzie brush technique. Samples were inoculated on Sabouraud’s dextrose agar media. The environment was monitored weekly by McKenzie brushing fungal cultures and scoring of culture growth. Investigators were blinded to the treatment regimens. All treatment groups improved over 9 weeks. The culture score of the combination shampoo (miconazole and chlorhexidine) was superior to placebo and chlorhexidine and significantly superior (P < 0.05) to all other treatments on week 3. The Wood’s lamp score was significantly lower at weeks 3 and 5 (P < 0.05) for the combination group than for the other treatment groups. The miconazole group was better than the placebo and chlorhexidine group with the chlorhexidine group being no better than the control group. The pretreatment environmental cultures were positive with similar scores in each group. The combination and miconazole groups were negative at week 2, weakly positive at week 3 and then negative subsequently. The chlorhexidine and control groups were negative on week 4 and subsequently thereafter. In conclusion the combination shampoo (miconazole and chlorhexidine) was superior to the miconazole shampoo and both of these were better than the placebo or chlorhexidine shampoo. There was a difference between the placebo shampoo and chlorhexidine shampoo.
In vitro susceptibility of canine bacterial isolates to fusidic acid in the USA
A. H. WERNER
Valley Veterinary Specialty Services, Studio City, California, USA
Fusidic acid is an antimicrobial steroid substance with a narrow antibacterial spectrum. The most susceptible organism is reported to be Staphylococci, with Streptococci and Enterococci being less sensitive. Gram-negative bacteria are generally resistant. It is not available in the USA, therefore acquired resistance to fusidic acid in this country would not be anticipated. The objective of this study was to evaluate the sensitivity to fusidic acid of bacteria isolated from canine patients. Sensitivities to standard antibiotics were also evaluated for each sample. Fifty (n = 50) samples from dogs living in the Los Angeles, CA, USA area were cultured and identified by standard laboratory procedures. Susceptibility testing was performed by agar disc diffusion method according to the manufacturers’ instructions. The majority of samples (n = 36) were isolated from urine, and 14 samples were isolated from skin. Five organisms were identified; Staphylococcus intermedius (five from urine, 11 from skin), Enterococcus spp. (nine samples, all from urine), Proteus spp. (11 from urine, and one from skin), E. coli (11 samples, all from urine), and Pseudomonas aeruginosa (two samples, all from skin). Sensitivity to fusidic acid was 44%, 33%, 17%, 0%, and 0%, respectively, which was similar to previous reports except for Staphylococcus intermedius, for which sensitivity was significantly lower than expected. Staphylococcal sensitivity to fusidic acid in cultures from people and dogs in Britain has been reported to be as high as 98%. Therefore, a more appropriate determination of efficacy and sensitivity will require larger sample sizes or in vivo drug evaluation.
Nodular dermatofibrosis in a mixed breed dog
L. G. CONCEIÇÃO, T. D. SOUZA and V. E. FABRIS
Universidade Federal de Viçosa, Viçosa, MG; Sociedade Educacional do Espirito Santo, Centro Superior de Vila Velha, ES; Faculdade de Medicina, Unesp, Botucatu, SP, Brazil
A 7-year-old mixed breed female dog was presented for the complaint skin tumours that had developed in the last 2 years. Physical examination revealed multiple firm skin nodules, approximately 1 cm in diameter, localized mainly on the face, thorax, hindlegs, and trunk. According to the owner, the lesions had increased in number but not in size. Serum biochemistry panel and CBC were normal. A mild proteinuria was seen on urinalysis. Histological examination of a skin biopsy showed a dome shaped exophytic mass with mature, redundant and haphazardly arranged cell-poor collagenous tissue that had partially displaced the adnexa. The mass was covered by a normal to slighted hyperplastic epidermis. Abdominal ultrasound examination revealed variably sized cystic cavities in the parenchyma of the left kidney; renal biopsy was not performed. The dog did well for almost 2 years after the initial evaluation, at which time it developed bacterial endocarditis and septicaemia and died. The necropsy findings included periodontal disease, mild pleural effusion, valvular endocarditis, pulmonary congestion and areas of renal infarction in the right kidney. The left kidney was twice normal size and had one large cystic cavity, along with some smaller ones, filled with a urine-like liquid. No evidence of metastasis was found. Histological examination of renal tissue showed papillary renal cystadenomas. This case is interesting because it illustrates a case of nodular dermatofibrosis and renal cystadenoma in a non-German shepherd dog. In addition, renal lesions were unilateral, suggesting a better prognosis.
Disseminated discoid lupus erythematosus in a dog
M. NAGATA, K. RINPOU and H. NANKO
Animal Dermatology Center, ASC, Tokyo; Rinpou Animal Hospital, Saitama; Tokyo Koseinenkin Hospital, Tokyo, Japan
The term ‘discoid lupus erythematosus’ (DLE) is used to describe LE involving only the skin. In people, DLE is classified into a localized and disseminated form. In dogs, DLE is used to describe a disease with lesions limited to one area, i.e. the face. We report on a case of generalized or disseminated DLE in a dog. A 12-year-old, male beagle dog was presented with a 1-month history of scaling and alopecia in the lumbosacral area. The dog had been treated previously with systemic antibiotics; however, the lesions rapidly worsened. At the time of examination, the dog had generalized scaling, alopecia, infiltrative erythema on the extremities and the bridge of the nose, hyperkeratosis on the footpads, and mild lymphadenopathy. Histological examination of a skin biopsy revealed hyperkeratosis, hydropic degeneration of the basal cell layer with an inflammatory infiltrate of lymphocytes and plasma cells, and mucinosis in the superficial dermis and periadnexal areas. Direct immunofluorescence testing of the skin biopsies revealed a linear deposition of IgG at the dermal–epidermal junction. A CBC showed mild anaemia and leukopenia, but an antinuclear antibody test was negative. This case closely resembles the description of humans with disseminated DLE. The dog improved with sun avoidance and systemic prednisolone therapy, but required continuous prednisone therapy.
Primary lymphoedema in a German shepherd dog
K. SHIBATA, M. NAGATA, M. YAMAGUCHI, M. AKIYAMA and H. NANKO
Animal Dermatology Center, ASC, Tokyo; M’s Animal Hospital, Kanagawa; Seta Animal Hospital, Tokyo; Tokyo Koseinenkin Hospital, Tokyo, Japan
Canine primary lymphoedema is a rare condition and most reported cases are congenital in onset. The following is a description of primary lymphoedema with in an adult dog. An 8-year-old, male German shepherd dog presented with a 6-month history of persistent swelling in distal extremities of the hindlimbs. The dog had been treated previously with systemic antibiotics but the swellings did not resolve. Upon physical examination, the dog’s general condition was otherwise good. The swellings were nonpainful, soft, pitting, and of normal temperature. Cell-poor, clear exudate from fistulas and nonerythematous papules were also seen in the affected areas. Histological examination of skin biopsies revealed hyperplasia and irregular dilatation of lymphatic vessels with severe fibrosis in the dermis. Complete blood counts, serum biochemical analysis, and TSH stimulation test all revealed no abnormalities. Thoracic radiographs and an electrocardiograph did not show any evidence of cardiac disease. Abdominal radiographs and magnetic resonance imaging of the abdomen and the hindlimbs also did not reveal any abnormalities compatible with a suspected lymphatic obstruction. Direct lymphography of hindlimbs was performed and a greatly increased number of lymphatic channels and ectasia of lymphatic vessels were seen. Based on these findings, the dog was diagnosed as having adult onset primary lymphoedema.
Crystal violet stain for cytological evaluation of Malassezia
L. CORNEGLIANI and A. VERCELLI
Ambulatorio Veterinario Associato, Torino, Italy
Cytology is a quick and useful diagnostic tool in veterinary dermatology. Hemacolor® and Diff-Quick® are the most widely used stains in clinical practice. We report on the use of crystal violet stain for the cytological identification of Malassezia using the acetate tape skin impression smear technique. Crystal violet, the first component of Gram stain, was chosen because of its intense colour and its ability to penetrate the walls of bacteria and yeast. After pressing the acetate tape to the skin, the tape was pressed onto a glass microscope slide over two drops of crystal violet stain. Excess stain was blotted with paper leaving the slide ready for immediate examination. Using this staining technique, 60 acetate tape impression smears were collected from 30 dogs with atopic dermatitis and secondary Malassezia infections. In order to evaluate the reliability of this technique, 30 samples were stained with Diff Quick® and 30 with crystal violet. Both groups were examined blindly. Ten fields per slide were examined and the mean number of yeast per HPF under oil immersion was calculated. There was no significant difference between the two groups.
Lufenuron: a new concept in the dermatophytosis therapy
L. Y. J. ANSAY
Clinique Vétérinaire la Haubette, Tinqueux, France
In November 1999, two cases of dermatophyte furunculosis that had been nonresponsive to conventional therapy responded to the administration of lufenuron (Program®). The first case involved a 7-month-old female Yorkshire terrier dog presented with a 5-month history of furunculosis caused by dermatophytosis confirmed by biopsy. The dog had not responded to oral griseofulvin at a dose of 20 mg kg−1 twice daily for 1 month and topical antifungal therapy (enilconazole, ketoconazole). The dog was later treated with oral griseofulvin at 50 mg kg−1 twice daily, but did not respond. A previous report on the successful use of lufenuron for the treatment of coccidioidomycosis prompted us to treat the dog with one oral dose of lufenuron 60 mg kg−1. Five weeks after treatment the dog was cured. The second case involved two dogs in the same household with furunculosis caused by dermatophytosis. The first dog had been treated unsuccessfully with griseofulvin at 50 mg kg−1 twice a day. At the request of the owner, this dog received lufenuron 60 mg kg−1 orally one time and responded. One of the owners’s other dogs, presumably infected by this dog, had responded to lufenuron within 3 weeks, hence the owner’s request. Lufenuron is a known inhibitor of chitin synthesis in insects and is used for the control and prevention of flea infestations. The authors who had treated the dog with coccidioidomycosis suggested that lufenuron somehow inhibits the synthesis of the cell walls of certain types of fungi.
Direct relationship between IgE concentration and mast cell TNF-α production in the dog
P. BRAZIS, L. l. FERRER and A. PUIGDEMONT
Facultat de Veterinaria, Universitat Autonoma de Barcelona, Spain
The role of IgE on mast cell (MC) activation is well known. Recent studies have demonstrated that IgE also has the ability to up-regulate the high affinity IgE receptor (FcεRI) on the surface of human and murine MCs, leading to an increased production of cytokines and chemokines. In the present study we investigated the influence of IgE concentrations on the synthesis of inflammatory cytokines such as TNF-α by canine skin MCs maintained in culture. Mature MCs were enzymatically dispersed from skin biopsies of six dogs and were cultured for up to 5 days in medium supplemented with recombinant canine SCF (6 ng mL−1) and in the presence of increasing serum IgE concentration (ranging from 0 to 80 μg mL−1). After that, skin MCs were activated with anti-IgE. TNF-α concentration was assessed 5-h post-MC activation by a cytotoxic bioassay. MCs cultured for up to 5 days in the presence of high serum IgE concentrations (8 μg mL−1) produced over four times more TNF-α (8 pg mL−1) than MCs cultured in absence of serum IgE, in response to stimulation with anti-IgE. We found no significant differences between the concentrations of TNF-α produced by MCs cultured in the presence or absence of serum IgE after activation with a nonimmunological stimulus (calcium ionophore A23187 and PMA). These results indicate a positive correlation between MC cytokine production and IgE concentration present during MC culture. An increase of FcεRI expression on MC surface induced by high concentrations of IgE may account for these findings.
Who’s afraid of amphotericin B (AmB)?
Clinique Veterinaire de Carros, Carros, France
Amphotericin B (AmB) is highly active in vitro against Blastomyces, Cryptoccocus, Malassezia, Histoplasma, and Leishmania. In water, the drug is present in three physical states: soluble monomers (the active drug), soluble oligomers and insoluble aggregates (most toxic). AmB solution (Fungizone®) is the less expensive form available. In this study, we report the use of various AmB treatment protocols for canine leishmaniasis. In the first protocol, it was rapidly infused intravenously (0.5–0.8 mg kg−1) over 15–45 s 2–3 times a week until an accumulated dose of 8–15 mg kg−1 was reached. In the second protocol, we used a mixture of AmB and lipids to reduce the acute toxicity. Currently, we use a mixture containing 1 mg mL−1 of AmB; we mix one bottle of 50 mg of AmB in 40 mL of sterile water and 10 mL Intralipid10%®. After hyperhydratation (50 mL kg−1 of normal saline followed by 10 mL kg−1 of 20% mannitol), doses from 1 to 2.5 mg kg−1 can be reached using this mixture. Adverse effects include anorexia, fever, vomiting and reversible renal insufficiency.
Hyposensitization in the dog: results of a retrospective study in France
P. BOURDEAU, A. GUILLOUX and P. BLUMSTEIN
National Veterinary School, Nantes and Maisons-Alfort, France
Many factors influence the success of hyposensitization therapy in dogs. The following is a retrospective summary of 65 cases of canine atopy presented to either the Veterinary School at Nantes or Maisons-Alfort between 1989 and 1996. The classical Willemse criteria were used for establishing a definitive diagnosis, including a positive intradermal skin test reaction to at least one allergen. Parasitic skin diseases and food hypersensitivities previously were excluded from the differential diagnosis. Dogs were hyposensitized using 1–5 allergens in aluminium hydroxide (ISOTEC Lab.). Historical and clinical information were collected from the medical records and, in addition, from a specific questionnaire and telephone interview. Eighty per cent of the dogs showed symptoms before 3 years of age. The dogs were between 2 and 9 years of age and 26 dog breeds were represented. Clinical signs included otitis (50.8%), conjunctivitis (36.9%), rhinitis (6.2%), and nonseasonal pruritus (92.3%). We found that 75% of dogs reacted positively to more than one allergen with 96% having reactions to D. farinae. Positive reactions to D. pteronyssinus were seen in 57% of dogs from Nantes and 16.7% from Paris. One third of the dogs were sensitive to pollens. Successful hyposensitization therapy was defined as a > 50% decrease in pruritus and was seen in 47.3% of dogs. A good response (25%–50% decrease in pruritus) was seen in another 13.2% of dogs. Clinical improvement was apparent in less than 9 months in 86% of cases. The following factors were found to have a positive influence on the success of therapy: age (> 5 years), sex (males), length of symptoms (clinical disease for > 1 year), a sensitization to nonseasonal allergens, treatment with 1–3 allergens, therapy for at least 1 year, and the quality of follow-up care. In 20 dogs, two had one allergen become negative (good response to treatment), and nine developed new hypersensitivities.
In vitro assay for detection of canine keratinocyte activation: preliminary results for pharmacological tests of activation/regulation
C. CADIOT, C. IBISCH, P. BOURDEAU and H. GATTO
National Veterinary School, Nantes; Virbac S.A. Laboratories, Carros, France
In humans, keratinocytes are known to produce TNF-α and to express ICAM-1 (CD54) when stimulated with IFNγ. The aim of this study was to evaluate an in vitro model of canine keratinocyte activation, and subsequent possibilities for studies on inhibition/regulation. Cultured canine keratinocytes (Kc) (0–30000 well−1) were stimulated by human recombinant IFNγ (25–400 ng mL−1) (Sigma) and LPS (2.5–40 μg mL−1) (Sigma), or with Phorbol-Myristate-Acetate (control). After various incubation times, supernatants were tested for TNF-α concentration in a cell viability assay using WEHI 164 cells. TNF-α concentrations were calculated using a TNF-α concentration scale and Softmax 3.1 software. PMA-stimulated canine Kc were labelled by antihuman ICAM-1 mAb (5.7 μg from Dako or 15 μg from Immunotech) (positive control: human cell line). Analysis was performed using Becton-Dickinson FACscan. TNF-α production in stimulated cells varied widely from 0.09 to 2.05 pg mL−1 (compared to 0.09–0.49 in controls). The best stimulations were obtained using confluent cultures, 6×105 Kc mL−1, 400 ng mL−1 IFNγ and 40 μg mL−1 LPS, at 48 h compared to 24 h (X 1.4–5.3) or to 72 h (X 1.8–3.25), with the exception of one experiment (X.0.7). The anti-ICAM-1 monoclonal antibodies did not stain PMA-activated Kc, suggesting that they cannot be used in dogs. In our hands, human rIFNγ and LPS increased 1.3–22.7 times TNF-α secretion (with wide interindividual variations). It is likely that these promising results could be improved by using canine IFNγ.
Evaluation of the efficacy of a 10% pyriproxyfen spot-on for the control of Otodectes cynotis in cats
P. Bourdeau and P. Cohen
National Veterinary School, Nantes; Clinique Vétérinaire Avenue de Laon, Reims, France
Otodectes cynotis is a common parasite in dogs and cats and is difficult to control in animal colonies. The purpose of this study was to evaluate the efficacy of pyriproxyfen (insect growth regulator) for the control of Otodectes infestation in cats. Twenty-three infested cats from a cattery were divided into three groups. Group A (n = 8) received one auricular treatment (four drops per ear) of pyriproxyfen 10% spot-on (Cyclio®, Virbac). Group B (n = 7) also received one auricular treatment (four drops per ear) but of fipronil (Frontline® spot-on, Merial). And finally, Group C (n = 8) received one subcutaneous injection of moxidectin 0.2 mg kg−1 (Cydectin®, Fort Dodge). On day 0 one ear per cat was treated in Groups A and B. The second ear was treated if necessary on day 7. If cats were infested on day 30, they received the alternate treatment. Cats were housed as a group during the study. This presented an opportunity to evaluate the preventive action of the therapies. The presence of parasites was evaluated on days 0, 7, 15, 30, 60, and 90. On day 7, mites were gone only from the pyriproxyfen and fipronil treated ears. This was interpreted as an absence of systemic effect of these topical formulations. The cats in the pyriproxyfen group were free of mites at least until day 30. In the fipronil treated group, six ears were found to be infested on day 15 (three from day 0) and on day 30 four ears were infested, suggesting a short preventive effect in the absence of body treatment. In the Cydectin group dead mites were found on day 15 and 0 mites on day 30. In the three groups, mites reappeared on days 60 and 90, indicating that the control is difficult to obtain with only a single treatment. These results show that pyriproxyfen is efficacious in the treatment of Otodectes compared to the other products.
The acaricidal effects of pyriproxyfen on Ornithonyssus bacoti: a new concept in control
P. BOURDEAU and C. MANGION
National Veterinary School, Nantes, France
Insect growth regulators traditionally are considered to only be effective against insects. The purpose of this study was to evaluate the efficacy of a pyriproxyfen on mites via an experiment with Ornithonyssus bacoti (Gamasida), an intermittent ectoparasite of rodents. A colony of naturally infected rodents were separated into two groups. Fifty mice were treated with a topical application (one drop per adult or one swab per juvenile with a drug impregnated cotton tip swab) of a 10% solution of pyriproxyfen. The second group (52 rats) were similarly treated with permethrin 40%+ pyriproxyfen 0.3% (Duowin® contact, Virbac). Rodents were treated on day 0 and day 45. The number of mites in the cages and on rodents (from standardized combing) was determined on days 0, 1, 8, 20, 42 and 150. Preliminary tests were performed to evaluate the tolerance of the two products used. In the mice, mites decreased 75% on day 1 and 100% from days 8 to 150. In cages, the decrease in mites was progressive: 37.5% on day 1, 62.5% on day 8, 50% on day 42, and 100% on day 150. In rats, mites decreased 91.6% on day 1 and then 100% thereafter. In cages, the decrease in mites also was progressive: 41% on day 1, 68.2% on day 8, 72.8% on day 42, and 100% on day 150. One year later the colony has remained free of Ornithonyssus. These results suggest a high degree of efficacy with some prophylactic effect even though the parasite does not immediately disappear from the environment. The rapid acaricidal effect may be useful to treat other mite infestations.
Effectiveness of Microderm vaccine against dermatophytoses in animals
M. G. MANOYAN, A. N. PANIN and K. P. LETYAGIN
The All-Russia State Research Institute for Control, Standardization and Certification of Veterinary Preparation (VGNKI), Moscow, Russia
During 1992–1998, intense research on the development and introduction of dermatophyte vaccines into veterinary practice was carried out in our laboratory (VGNKI). Epidemiological studies in Russia and countries of CIS on animal dermatophytosis (cats, dogs, fur-bearing animals, rabbits) has shown that the most common aetiological agents are Microsporum canis (69%) and Trichophyton mentagrophytes (20%). From the samples collected, we were able to choose highly productive strains of dermatophytes for research on their biology and immunological properties for the development of a monovalent vaccine, and for their suitability for use in experimental animals. Studies revealed that live attenuated dermatophyte vaccines had greater immunological activity than inactivated ones. The dermatophtye vaccine, ‘Microderm’ contains microconidia of avirulent strains M. canis and T. mentagrophytes. The vaccine is intended for both treatment and prevention of dermatophytosis in animals (cats, dogs, fur-bearing animals and rabbits). It is administered twice at 10–14-day intervals by intramuscular injection. The dose depends upon the species and age of the animal. In studies with more than 3000 animals, ‘Microderm’ has been shown to be effective in the treatment and prevention of Microsporum and Trichophyton infections.
Epidemiology of canine atopic dermatitis in Japan
T. IWASAKI, J. HOSOKAWA, K. YAMASHITA and T. ODAGIRI
Veterinary Medical Teaching Hospital, Gifu University, Gifu; Hitachi Chemical Co. Ltd, Hitachi, Ibaraki, Japan
A questionnaire was sent to 185 Japanese veterinarians to collect information on the epidemiology of canine atopic dermatitis. Respondants reported on 2168 dogs with atopic dermatitis that had been seen between June 1998 and June 1999. The diagnosis of atopic dermatitis was based on the criteria proposed by Willemese after exclusion of ectoparasites, seborrhea and primary pyoderma. Control data were obtained from dogs without skin disease that were admitted to veterinary hospitals. Respondents were asked to report sex, breed, and age at onset, season of birth, house location, type of house and reactive allergens as determined by serum-IgE concentrations using CMG IMMUNODOT. Male dogs accounted for 45.2% and females 54.5% (P < 0.01) of the population. Only 9% and 16.8% of male and female dogs, respectively, were surgically neutered. Dog breeds affected included Shih tzu (24.4%), mixed (13.7%), Shiba (12.2%), golden retriever (8.3%) and Shetland sheepdog (5.4%). For season of birth, the following was reported: spring (25.6%, P < 0.05), summer (23.0%), autumn (20.4%) and winter (21.0%). Spring was the most frequent season of birth for atopic dogs. Age of onset varied between 6 months to 3 years in 78.8% of dogs. Symptoms in atopic dogs in the northern part of Japan tended to be exacerbated in winter, whereas most dogs in other areas showed nonseasonal symptoms. Allergens were investigated in 838 dogs. The most commonly reported allergens were house dust mites (55%), grass mix (33%), Japanese cedar (30%) and mugwort (18%). This work was supported by a Grant-in-Aid from the Ministry of Education, Science, Sports and Culture (#10839007).
Effectiveness and practicality of cryosurgery in small animal practice for the treatment of feline dermatoses
R. LUCAS and C. E. LARSSON
University of São Paulo, São Paulo, Brazil
There is little information in the literature on the use of cryosurgery in cats. In this study, we report on the practicality and effectiveness of this treatment. Fifty cats were used in this study. Cats were treated with cryosurgery using liquid nitrogen as a cryogen via spray or probe (Cry-Ac3 Brymill Corporation, USA). Affected cats had preneoplastic or neoplastic lesions (8% and 82%, respectively), granulomatous lesions (6%), hyperplastic lesions (2%), and non-neoplastic tumour lesions (2%). We observed a complete remission in 80.5% of treated lesions with a corresponding cure rate of 70% in the cats. Cryosurgery was considered practical and safe for use in small animal practice. Supported by the University of São Paulo.
Effectiveness and practicality of cryosurgery in small animal practice for the treatment of canine dermatoses
R. LUCAS and C. E. LARSSON
University of São Paulo, São Paulo, Brazil
There is little information in the literature on the use of cryosurgery in dogs. In this study, we report on the practicality and effectiveness of this treatment. Fifty dogs were used in this study. Dogs were treated with cryosurgery using liquid nitrogen as a cryogen via spray or probe (Cry-Ac3 Brymill Corporation, USA). Affected dogs had skin tumours (86%), hyperplasic lesions (6%), papilloma (6%) and other lesions (2%). We observed a complete remission in 95.3% of treated lesions with a corresponding cure rate of 90% for dogs. Cryosurgery was considered practical and safe for use in small animal practice. Supported by the University of São Paulo.
An outbreak of Microsporum canis infection in a cat, two goats and their owners
L. PINTER, R. M. ANTHONY and M. DROBNIC-KOŠOROK
Veterinary Faculty, University of Zagreb, Croatia; King’s College London, St. Thomas’ Hospital, London, UK; Veterinary Faculty, University of Ljubljana, Slovenia
Microsporum canis infection developed in a cat, two goats, and the animals’ owners. The historical, clinical, and treatment features are described. Three weeks prior to outbreak, the owners adopted a feral cat that had clinical lesions suspicious of M. canis infection. Two weeks later suspect lesions were noticed in two goats, as well as in the male and female owners with whom the cat had daily contact. Lesions were located on the haired areas of the trunk and on the udder of the goats. The female owner had suspect lesions only on her arms while her husband had lesions on his arm and caudal neck. Specimens were collected from suspect lesions and were incubated at 27°C for 3–4 weeks. The morphology of the thallus and microscopic appearance of the hyphae, macroconidia and microconidia identified suspect dermatophyte cultures. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of all M. canis isolates revealed no differences in protein patterns. Lesions in the people resolved after 4 weeks of topical terbinafine therapy. The goats were treated with partial clipping of hair surrounding lesions. The cat was treated with a combination of twice-weekly ketoconazole baths and ketoconazole 10 mg kg−1 for 6 weeks. After all of the lesions had resolved in all animals, they were fungal cultured using the hairbrush technique; all fungal cultures were negative.
Distribution of cutaneous mast cells at pruritic and nonpruritic sites and in dogs with and without atopic dermatitis
H. P. HUANG, P. H. CHANG and M. K. LAI
Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
Pruritus is the hallmark of atopic dermatitis (AD). Part of the pathophysiology involves the release of inflammatory mediators from degranulated mast cells. The purpose of this study was to investigate the distribution of mast cells in pruritic and nonpruritic skin sites and in atopic and nonatopic dogs. Nine atopic dogs and 19 dogs without clinical signs or a history of skin disease were used in this study. Skin biopsy samples were obtained using a disposable skin biopsy punch. Samples were obtained from sites predisposed to pruritus in AD (face, abdomen, and rump) and from sites less predisposed to pruritus (i.e. nonpruritic sites). Skin samples were routinely fixed, processed for histological examination and stained with Toluidine blue. All dogs were free from any signs of skin disorders at the time the skin samples were taken.
There was no significant difference (P = 0.05) in the number of mast cells counted between dogs with and without AD. There was, however, a significant difference (P = 0.04) in mast cell counts at sites predisposed to pruritus between dogs with and without AD. The number of mast cells was not significantly different (P = 0.07) at nonpruritic sites between dogs with and without AD. Mast cell counts were significantly different (P = 0.008) between pruritic and nonpruritic sites in dogs affected by AD; however, there was no significant difference in mast cell counts in nonatopic dogs between pruritic and nonpruritic sites (P = 0.15). Higher mast cell numbers at particular body sites may explain the pattern of pruritus seen in atopic dogs. The study was self-funded.
see Table 4.
Skin characteristics measured by trans-epidermal water loss, corneometry and sebometry are not valuable tools to evaluate the effects of topical treatments in dogs
D. GROUX and E. BENSIGNOR
Veterinary Clinic, Reignier; Veterinary Clinic, Paris, France
The assessment of skin hydration and microclimate has been the subject of recent studies in veterinary medicine. A validation of these techniques in dogs is mandatory. The goals of this study were to evaluate physiological data about normal canine skin, their variation with the use of topical treatments and their reproducibility. The parameters considered were the trans-epidermal water loss (TEWL), the measure of the hydration of the stratum corneum, and the lipid content by sebometry. Ten clinically normal Labrador retriever dogs were studied. Eight skin sites were selected. Baseline measurements were made at 0 time and at 24 h. Four antiseborrhoeic shampoos were tested. The negative control site consisted of water only and the positive control site consisted of a detergent. Measurements were made at 0, 7, 17 min and 77 min after application. Sebometry was statistically higher in ear pinnae compared to other the sites. Corneometry was statistically higher in ear pinnae and lower on the rump and the neck compared to other sites. None of the tests (TEWL, corneometry and sebometry) gave reproducible results between day 0 and day 1. No statistical difference was observed between the different shampoos, water only and the detergent. These methods proved to be simple, painless, noninvasive and suitable for use in a clinical environment. These assessment criteria were not useful in comparing various topical therapies in dogs. However, they may be helpful in studying skin changes in various skin diseases and understanding the underlying mechanisms of cutaneous disorders. Supported by a grant from Bayer-Pharma.
A clinicopathological study of skin neoplasms in ruminants
K. FOUAD, H. GOHAR, M. EL-MAHDY and A. ABU-SEIDA
Faculty of Veterinary Medicine, Cairo University, Cairo, Egypt
Records from 5647 small and large ruminants (camels, cattle, buffaloes, sheep and goats) in Egypt were reviewed. The purpose of this study was to determine the most common skin tumours in these species. Skin neoplasms were recorded in 35/5647 (0.62%) of the cases. The most common skin tumours were cutaneous papillomas, squamous cell carcinomas, basal cell carcinomas and sweat gland adenomas. Surgical excision of cutaneous papillomas resulted in resolution of smaller nodules within 3 weeks; lesions did not recur. Basal cell carcinomas were excised and wounds healed by second intention within 60 days. Supported by a grant from Post-Graduate Studies Department, Cairo University.
Dermoid cysts in camels
K. FOUAD, H.M. GOHAR, M. EL-MAHDY and A. ABU-SEIDA
Faculty of Veterinary Medicine, Cairo University, Cairo, Egypt
The purpose of this study is to report on the prevalence of dermoid cysts in camels and on their response to surgical treatment. In this study, 1798 camels of different ages and both sexes were examined clinically for the presence of dermoid cysts. Any observed cysts were surgically excised using tranquilization and infiltration with a local anaesthetic. Dermoid cysts were diagnosed in 37 camels. The clinical history revealed that they were congenital and grew slowly in size. There were 22 males and 15 females affected. The camels ranged in age from 8 months to 15 years of age. Clinically, the cysts were well circumscribed, 3–14 cm in diameter, fluctuant, freely movable and painless. The most common location was the anterolateral aspect of the upper third of the neck. On gross examination, the internal surface of the cyst was uneven and often had more than one pocket. The cysts often contained hair tufts mixed in a gray-coloured greasy secretion. A thin coffee-coloured fluid filled the centre. Histological examination revealed that the lumen was lined by epidermis covered with a thick layer of keratin thrown into folds containing pigmented material. The basal layer of the epidermis showed a large number of melanocytes. The dermis contained focal aggregations of sweat and sebaceous glands together with hair follicles in a connective tissue stroma. Multiple focal areas of melanocytic cells were found in dermal connective tissue within muscle fibres. Supported by a grant from Post-Graduate Studies Department, Cairo University.