RADIOGRAPHIC DIAGNOSIS OF MECHANICAL OBSTRUCTION IN DOGS BASED ON RELATIVE SMALL INTESTINAL EXTERNAL DIAMETERS

Authors

  • Cyrielle Finck,

    1. Companion Animal Research Group, Departement de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montreal, Saint-Hyacinthe, Quebec, Canada
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  • Marc-André D'Anjou,

    Corresponding author
    1. Companion Animal Research Group, Departement de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montreal, Saint-Hyacinthe, Quebec, Canada
    • Address correspondence and reprint requests to Marc-André d’Anjou, Centre Vétérinaire Rive-Sud, 7415 boulevard Taschereau, Brossard Québec, J4Y 1A2. E-mail: madvetrad@gmail.com

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  • Kate Alexander,

    1. Companion Animal Research Group, Departement de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montreal, Saint-Hyacinthe, Quebec, Canada
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  • Swan Specchi,

    1. Companion Animal Research Group, Departement de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montreal, Saint-Hyacinthe, Quebec, Canada
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  • Guy Beauchamp

    1. Companion Animal Research Group, Departement de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montreal, Saint-Hyacinthe, Quebec, Canada
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  • Portions of this paper were presented at the annual scientific meeting of the American College of Veterinary Radiology, Las Vegas, October 18–21, 2012.

Abstract

Mechanical obstruction is a frequent cause of acute vomiting in dogs requiring prompt diagnosis to improve patient management and prognosis. The purpose of this retrospective study was to compare small intestinal radiographic characteristics in dogs with versus without mechanical intestinal obstruction. Fifty dogs with gastrointestinal clinical signs and abdominal radiographs were recruited from hospital record archives and assigned to groups (group 1, obstructive, n = 25; group 2, nonobstructive n = 25). Abdominal radiographs were randomized and independently interpreted by three examiners who were unaware of group status. Intestinal dilation was subjectively scored based on distribution (segmental, regional or diffuse), and severity (absent, mild, moderate or severe). Small intestinal maximal diameter (SImax), L5 vertebral body height, small intestinal minimal diameter (SImin), and an estimated average of small intestinal diameters (SIave) were measured and three ratios were calculated: SImax/L5, SImax/SImin, and SImax/SIave. Segmental dilation was more prevalent in obstructed dogs for all examiners (P ≤ 0.03) and most nonobstructed dogs had no dilation (P ≤ 0.05). All ratios were higher in obstructed dogs (P < 0.002). Subjective dilation scores and ratio measurements had low interobserver agreement (absent to fair, with kappa values between −0.06 and 0.57) and reproducibility (coefficients of 0.35–0.61). Findings indicated that dogs with SImax/L5 ≤ 1.4, SImax/SImin ≤ 2, and SImax/SIave ≤ 1.3 values are very unlikely to be mechanically obstructed; dogs with SImax/L5 ≥ 2.4, SImax/SImin ≥ 3.4 and SImax/SIave ≥ 1.9 are very likely obstructed, particularly if segmental dilation (less than 25% of the small intestine) is present. Dogs with ratios falling between these thresholds may need further testing unless other signs justify surgical exploration or endoscopy.

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