The work was done at the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University.
Clinical Features and Outcome of Heterobilharzia americana Infection in Dogs
Article first published online: 30 NOV 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 1, pages 140–144, January/February 2010
How to Cite
Fabrick, C., Bugbee, A. and Fosgate, G. (2010), Clinical Features and Outcome of Heterobilharzia americana Infection in Dogs. Journal of Veterinary Internal Medicine, 24: 140–144. doi: 10.1111/j.1939-1676.2009.0429.x
- Issue published online: 4 JAN 2010
- Article first published online: 30 NOV 2009
- Submitted July 24, 2009; Revised September 17, 2009; Accepted October 9, 2009.
- Blood fluke;
Background: Heterobilharzia americana (HA), the causative agent of canine schistosomiasis, is a flatworm with a freshwater snail as an intermediate host. Only case reports or small case series evaluating naturally infected dogs have been published.
Objective: Describe clinical signs in dogs naturally infected with HA.
Animals: Twenty-two dogs naturally infected with HA from 1985 to 2009.
Methods: Retrospective study. All medical records were searched for HA and schistosomiasis. Only dogs with a diagnosis based on identification of ova on histopathology or fecal saline sedimentation were included.
Results: The median age was 3.1 years (1–12). The median duration of clinical signs before diagnosis was 0.63 months (0.03–12). The most common clinical signs were lethargy (91%), weight loss (77%), hyporexia (68%), vomiting (59%), and diarrhea (55%). Eleven of the 22 dogs were hypercalcemic. Hypercalcemia did not resolve without definitive treatment with praziquantel. HA infection was an incidental diagnosis in 7/22 dogs. Diagnosis was obtained via necropsy (4), histopathology (9), and fecal examination (9). Definitive treatment included praziquantel and fenbendazole. Eighteen dogs were diagnosed antemortem and 17 were treated. Twelve dogs were alive for 6 months to 3 years after diagnosis.
Conclusions and Clinical Importance: HA infection occurs in younger, larger breed, indoor dogs. Hypercalcemia does not resolve without praziquantel treatment. Prognosis is good and neither hypercalcemic-induced renal failure nor ascites appears to worsen prognosis. Dogs in affected areas or that have traveled to affected areas that present for weight loss, gastrointestinal or liver disease, and hypercalcemia, should be tested.