An evaluation of the usefulness of invasive and non-invasive methods used to diagnose Helicobacter spp. infections in dogs.

The aim of this study was to assess the suitability of invasive and non-invasive methods used to diagnose Helicobacter spp. in the stomachs of dogs. The study was carried out on 30 dogs of both sexes and different breeds, between one and 15 years old. A histopathologic examination, a microbiological culture, a rapid urease test, a direct bacteriological preparation and a nested PCR assay were carried out. Gastric Helicobacter spp. was identified in gastric biopsy specimens from 16 (53.3%) dogs using direct bacteriological preparation, in four (13.3%) dogs based on a culture, in 23 (76.6%) dogs using the rapid urease test and in 21 (70,0%) dogs based on a histopathological assessment of the biopsy specimens. The nested PCR of the gastric biopsy specimens revealed gastric Helicobacter spp. in all the dogs (100%). A saliva PCR assay revealed gastric Helicobacter spp. in 23 (76.6%) dogs, while stool PCR revealed the bacterium in seven (23.3%) dogs. We found that invasive methods were more accurate than non-invasive methods in detecting a Helicobacter spp. infection in dogs. In addition, the nested PCR method used to evaluate the gastric mucosal biopsy specimens was the most accurate test for detecting Helicobacter spp. It was further found that the PCR-based saliva assay was the best non-invasive method for detecting Helicobacter spp. However, taking into consideration that most of the diagnostic methods used to detect this bacterium have drawbacks, at least two diagnostic methods should be used to detect Helicobacter spp. as is done in human medicine.