COMMENTARY
This study provides preliminary support for more selective use of abdominal ultrasonography in dogs with chronic vomiting.
Based on the population evaluated at the authors' referral institution, ultrasonography would have the highest diagnostic
utility in an older patient with suspected neoplasia. In contrast, the yield of abdominal ultrasonography in a younger dog
with minimal clinical suspicion of neoplasia will likely be lower, and the authors concluded that gastroduodenoscopy with
biopsy would allow a definitive diagnosis without the added expense of ultrasonography.
Several caveats must be made before these conclusions are extrapolated to other dog populations or veterinary practices. First,
the diagnostic utility of ultrasonography was only assessed in those patients with a final diagnosis of gastrointestinal disease.
In many cases of chronic vomiting, it is unclear before ultrasonography whether the cause of this clinical sign is solely
due to gastric or intestinal disease, and, thus, this imaging modality is used to evaluate multiple intra-abdominal organs.
If the authors had included those cases in which the final clinical diagnosis was renal or hepatic disease, for example, then
the reported diagnostic utility may have been unpredictably increased or decreased.
Second, all ultrasound examinations of dogs in this study were performed by a single board-certified radiologist. Thus, the
likelihood of identifying subtle pathologic changes within the abdomen was likely higher than what would be anticipated if
ultrasonography was performed by other specialists or general practitioners, and the diagnostic utility may have been higher
than most veterinarians should expect.
Finally, because this study was performed at a referral institution, some causes of chronic vomiting, such as pancreatitis,
foreign bodies, and intussusceptions, which may be easier to identify by nonspecialty trained ultrasonographers before referral,
would have been lower in the final population. If this study had been performed at a primary care facility, these diagnoses
may have made up a larger percentage of the study population and, thereby, increased the overall diagnostic utility of abdominal
ultrasonography calculated by the study authors.
One of the most important points highlighted by this study is that veterinarians should continue to evaluate the utility of
specific diagnostic tests in specific populations. Performing diagnostic tests on animals without fully appreciating their
overall usefulness may lead to increased patient mortality secondary to unnecessary client expense. This report concentrates
on a small group of patients with a particular subset of diseases, but it makes important points that enforce the problem-oriented
approach to diagnosis and, thus, may affect the decision-making process when evaluating patients with other presenting complaints.
Leib MS, Larson MM, Panciera DL, et al. Diagnostic utility of abdominal ultrasonography in dogs with chronic vomiting. J Vet Intern Med 2010;24:803-808.
The information in "Research Updates" was provided by Scott Owens, DVM, and Barrak Pressler, DVM, PhD, DACVIM, Department
of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907.
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