Introduction
Helicobacter infection in dogs is usually sub-clinical, meaning that owners will not notice any outward signs of discomfort or disease. However, when the bacterial infection does cause clinical signs, they tend to reflect severe gastric distress, and owners will want to obtain a conclusive diagnosis quickly. Helicobacter infection can lead to persistent vomiting, diarrhea, nausea, anorexia, weakness, weight loss and other gastrointestinal discomfort. Fortunately, there are a number of diagnostic tests that can be used to confirm Helicobacter infection.
Tests for Helicobacter Infection
Your veterinarian probably will recommend drawing blood to run a complete blood count and a biochemistry panel. While these tests cannot actually be used to diagnose Heliobacter infection, they may reflect nonspecific changes caused by fluid and electrolyte loss due to vomiting and diarrhea. They also can help rule out other systemic causes of gastric distress. A non-invasive diagnostic tool for Helicobacter infection is the urea breath (or blood) test, which involves giving the dog a radiolabeled-urea test meal and subsequently assessing whether the urea was taken up by Helicobacter bacteria. Unfortunately, this test is not widely available.
Gastric biopsy is the gold standard for definitively diagnosing Helicobacter. This procedure is done with the dog under sedation. Your veterinarian will pass an endoscope through the dog’s mouth and down its esophagus into the stomach. This will let the veterinarian visualize the inside of the stomach and obtain tissue samples from several different areas. These samples will be submitted to a laboratory for assessment on a microscopic level by a pathologist. Impression smears from the biopsy samples is another sensitive and easy test to perform, using various stains to make the bacteria more readily visible under a microscope. Another way to obtain stomach samples is to enter the stomach surgically, through the abdominal cavity. This is much more invasive and risky than getting the samples using an endoscope.
A rapid urease test can also be performed on samples taken endoscopically from the stomach. This is one of the quickest and most accurate tests for Helicobacter and involves putting a biopsy sample from the stomach into a urea broth with phenol red added as a pH indicator. Results can be read in a few hours, and certainly within 24 hours, in the form of a color change in the broth.
Blood samples taken in order to culture Helicobacter are rarely helpful, as the organisms are difficult to culture and the test requires special techniques. Other diagnostic tests include serology and a polymerase chain reaction test (commonly called “PCR”). However, these tests are not widely available.
If your dog is suffering from unexplained bouts of vomiting, diarrhea or other forms of gastrointestinal distress, take him to the veterinarian promptly. Getting an actual sample of the stomach lining is far and away the most reliable way to confirm active Helicobacter infection.