TDK conference 2019

Circovirus (CaCV) detection in dogs was first reported in the USA in 2012, and its presence in Hungary was confirmed by PCR testing of endoscopic gastric and intestinal biopsies. Limited data are available on the prevalence of circovirus infection in the domestic canine population; the clinical importance of the disease, and the practical and cost-effective way of detecting the virus.

This study aims to compare the results of circovirus PCR analysis of gastric and intestinal biopsies of dogs and fecal samples of the same animal arrived in the Endoscope Laboratory of the Departement and Clinic of Internal Medicine, University of Veterinary Medicine Budapest for upper gastrointestinal endoscopy because of gastric and intestinal complaints. We would like to have a conclusion arising from the results regarding the CaCV prevalence in Hungary and the appropriate sampling.

In our research, 16 animals were included (average age: 6,4 years, 2 to 13 years of age, 10 females and 6 males), 16 gastric biopsies, 14 intestinal biopsies, and 16 fecal samples were obtained from the dogs. The dogs were selected randomly. An individually designed primer was used during the PCR analysis which, compared to the NCBI database, was 100% consistent with canine circovirus isolates. As a positive control, a sample from a clinical case was used. Which dog had at least one positive sample was considered infected. We found that 9/16 samples were positive for gastric and 9/14 for duodenal biopsies and 9/16 samples for feces were positive, too. Of the 16 dogs, 15 had at least one positive sample. Of the 7 negative feces samples, 6 were positive for gastric and/or intestinal biopsy. Of the 9 positive intestinal biopsies, 4 had a negative gastric biopsy and 3 of the 5 negative intestinal biopsies had a positive gastric biopsy.

Our results indicate that circovirus infections are highly prevalent in Hungarian domestic dogs undergoing endoscopic examination for gastrointestinal complaints. The small number of samples due to the high cost of testing made it difficult to evaluate the test results accurately but it is also evident from the results that a negative fecal PCR test does not exclude circovirus infection in dogs. A positive fecal PCR test result is not always associated with endoscopic gastric and small intestinal biopsies positivity. It can also be stated that routine endoscopic examination and biopsy sampling does not necessarily lead to contamination of samples from the stomach and duodenum since the positivity of one type of the biopsy sample was not always accompanied by the positivity of the other type. For further investigation of the clinical relevance of circovirus infection, it requires a cheaper and cost-effective method, like PCR screening of fecal samples against endoscopic biopsies to form a group of infected individuals.