Helicobacter Infection in Dogs
Helicobacter bacteria are typically harmless residents of the intestinal tract across various species, including domestic animals like dogs, cats, ferrets, and pigs, as well as wild animals like cheetahs and monkeys, and in humans. While Helicobacter pylori causes significant gastric infections in humans, leading to conditions such as gastritis, gastric tumors, and peptic ulcers, the role of Helicobacter in dogs and its connection to gastric issues remains largely uncertain (Note: H. pylori is not found in dogs).
Different species of Helicobacter have been identified in the stomachs of cats, and cases of mixed infections can complicate diagnosis. Among dogs, the most prevalent forms of Helicobacter include Helicobacter felis and Helicobacter heilmannii. Additional species found in dogs include Helicobacter rappini and Helicobacter salomonis. These bacteria typically reside within the mucosal lining and glandular cavities of the stomach.
There have been sporadic reports of Helicobacter isolation from the livers of dogs with hepatitis, but these instances remain anecdotal. Eradicating Helicobacter infection completely proves challenging and may persist for months to years, potentially lasting a lifetime in some dogs.
Symptoms
Many cases of Helicobacter infection in dogs manifest without any noticeable symptoms. However, in some instances, the following signs may be observed:
- Vomiting
- Dehydration
- Reduced appetite
- Audible bowel sounds
- Abdominal pain
- Weight loss
- Diarrhea
- Weakness
- Sudden death
Causes
The infection with gastric Helicobacter felis, Helicobacter heilmannii, Helicobacter rappini, and Helicobater salomonis occurs without a clearly defined transmission method. However, its higher occurrence in shelter dogs suggests the possibility of oral and/or fecal transmission. This notion finds support in the detection of Helicobacter-like organisms (GHLOs) in the vomit, feces, and saliva of infected animals. Additionally, there is suspicion that water may serve as a transmission medium, given the presence of GHLOs in certain surface waters.
Poor sanitary conditions and overcrowded environments seem to promote the spread of infection.
Diagnosis
Diagnosing Helicobacter infection definitively presents challenges in most cases. Your veterinarian will conduct a comprehensive physical examination along with routine laboratory tests, including a complete blood count, biochemistry profile, and urinalysis. Additionally, your veterinarian may obtain a sample from the stomach wall and stain it with May-Grünwald-Giemsa, Gram, or Diff-Quik stains, enabling the organism’s visibility under a microscope.
Endoscopic examination proves invaluable for directly observing the stomach walls and obtaining tissue samples for further analysis. This procedure employs an endoscope, a flexible tube with a camera at its end, inserted into the stomach via the esophagus. Polymerase chain reaction (PCR) tests are commonly employed to confirm Helicobacter presence in a sample and distinguish between Helicobacter species. However, confirmation can also be achieved by examining a tissue sample taken during endoscopy under a microscope.
It’s important to note that the presence of gastric Helicobacters in the body doesn’t necessarily indicate an infection requiring treatment.
Treatment
Since this disease is not thoroughly characterized in animals, there isn’t a universally accepted treatment regimen. If no apparent symptoms are present, treatment is typically not initiated. In contrast, in humans, treatment is initiated upon the detection of a Helicobacter infection, regardless of the presence of clinical symptoms, due to the potential risk of stomach cancer. However, this does not seem to be the case with dogs, so further action is generally not taken unless symptoms warrant it. If chronic vomiting or inflammation of the gastric lining occurs, treatment focuses on alleviating these symptoms, often through fluid therapy to address fluid loss.
For dogs diagnosed with a Helicobacter spp. infection, antibiotics along with acid-controlling drugs constitute the recommended treatment course, typically lasting two weeks. A follow-up examination with your veterinarian is necessary several weeks after the initial treatment to assess its success. In many instances, the infection or presence of bacteria may recur, though it’s unclear whether this results from recrudescence (a reactivation of the infection after dormancy) or reinfection from an external source.
Living and Management
Dogs harboring the Helicobacter bacterium are prone to stomach upset, so transitioning them to easily digestible food is recommended. If gastritis (inflammation of the gastric lining) is present, your veterinarian can guide you in implementing an elimination diet to avoid foods that may disrupt your dog’s digestive tract.
This disease often occurs in environments characterized by overcrowding and poor hygiene. If you own multiple animals, ensure they have adequate space and a clean living environment. Given that this bacterium can contaminate surface water, it’s advisable to prevent your dogs (and other pets) from drinking from streams, ponds, or rivers.
While this bacterial infection is suspected of being zoonotic between cats and humans, this is not the case for dogs and humans. Nonetheless, discuss any concerns with your veterinarian and adhere to the recommendations provided by your healthcare professional.