TDK conference 2017

The exact role of gastric Helicobacter-like organisms (GHLO) in the pathogenesis of gastritis and gastric tumours in dogs is still unclear, a cost-effective method of proving their presence is important to have in daily clinical practice. The aim of our work is to detect GHLO using the 13C-UBT (Urea Breath Test) in dogs undergoing gastroscopy. Our results were compared to the results of histopathologic and PCR examination of gastric biopsies obtained via endoscopy. Our further purpose was to introduce the 13C-UBT into everyday clinical practice as a cheaper and less invasive method than endoscopic sampling and PCR.

During our study, we examined 24 dogs (7 males, 17 females; age: 7 months - 14 years and 1 month, mean: 6 years and 3 months) using 13C-UBT. These dogs were referred to the Department and Clinic of Internal Medicine at the University of Veterinary Medicine with gastrointestinal symptoms. In 11 cases (5 males, 6 females, age: 2 years and 8 months – 11 years and 9 months, mean: 6 years and 3 months), gastroscopy and biopsy sampling were performed, histopathologic and PCR examinations were conducted to detect GHLO infection from the biopsies. The histological processing (modified Giemsa stain, hematoxyllin and eosin staining) of the biopsies obtained during the endoscopic examination was performed at the Department of Pathology. An individually designed genus specific primer based on the 16S rRNA gene was used for the PCR, the positive control was a Helicobacter pylori strain. The UBT samples were examined with an infrared isotope spectrometer, using the internationally approved cut-off value (2,5‰) as basis for interpreting the results. Based on the outcome of the UBT, the sensitivity, specificity, positive and negative predictive values were calculated. Correlation between the results of the UBT and the histopathologic examination was determined by Spearman’s rank correlation method.

The UBT was positive in 17/24 (70,8%) cases (mean: 17,8‰, range: 3,0-55,2‰). 3/11 animals were positive by PCR (27,3%), the UBT result of these dogs was positive, too, the sensitivity of the UBT is 100%. From the 8/11 animals found negative by PCR (72,8%), 4 were negative by UBT as well, the specificity of the UBT is 50%. The histopathologic examination was positive in 5/11 cases (45,5%), among these, 2 mild, 2 medium and 1 severe infections were detected. Correlation is proven between the scale of infection determined by histopathology and the extent of the UBT result (ρ: 0.78; p: 0.0006).

Based on experiences from our study, 13C-UBT can be successfully implemented during clinical practice and due to its simplicity and high sensitivity, it could become an important diagnostic tool for GHLO detection in the examination and diagnosis of dogs having gastric problems. However, the high number of false positive results limits the reliability of the test and it cannot supersede gastroscopy and the histopathological analysis of gastric biopsies.