Stomach Infection with Helicobacter in Cats


PetMD Editorial

Published Nov. 9, 2009

Helicobacter Infection in Cats  

The  Helicobacter bacteria are normal inhabitants of the intestinal tract, being found in several species, including domestic animals such as dogs, cats, ferrets and pigs, in wild animals such as cheetah's and monkeys, and in humans. Under normal conditions, the Helicobacter bacteria appear to be harmless to cats. While gastric infection due to Helicobacter pylori is a major health problem in humans – it has been associated with gastritis, gastric tumor, and peptic ulcer in affected people – the significance of this bacteria in cats and any correlation to gastric dysfunctions is still largely unclear.

Various species of Helicobacter organism have been isolated from the stomachs of cats and mixed infections can present, which sometimes complicates the diagnosis. Helicobacter pylori has been isolated in the stomachs of cats, and it is thought that humans may be susceptible to acquiring the bacteria from cats carrying it, or vice versa, but so far this is only an  assumption and the frequency of cats found carrying this form of Helicobacter is very low.  The most common forms of Helicobacter found in cats are Helicobacter felis and Helicobacter heilmannii. The bacteria inhabit the mucosal lining of the stomach, and the glandular cavities.

Infection from this bacteria is difficult to eradicate entirely and may last from months to years – even for a lifetime, in some cats.

Symptoms and Types

  • In most cases no symptoms may be seen
  • Vomiting
  • Dehydration
  • Poor appetite
  • Abdominal pain
  • Weight loss
  • Weakness


Gastric Helicobacter felis, Helicobacter heilmannii, and rarely, Helicobacter pylori infection. The method by which this infection is transmitted remains unknown, but because of its higher prevalence in shelter cats, oral and/or fecal transmission is considered a possibility. This assumption is supported by the presence of Helicobacter-like organisms, called GHLOs, in the vomit, feces and saliva of animals that have been infected. There is also some suspicion that the bacteria may be transmitted by water, as GHLOs have been found in some surface waters.


Establishing a definitive diagnosis of Helicobacter infection is difficult in most instances. Your veterinarian will perform a complete physical examination with routine laboratory tests including a complete blood count, biochemistry profile, and urinalysis. Your veterinarian may also take a sample from stomach wall and stain it with May-Grünwald-Giemsa, Gram, or Diff-Quik stains, which can easily demonstrate the presence of this organism by making it visible under microscope. 

 An endoscopic examination is of great help for direct observation of the stomach walls as well as for taking tissue samples for further processing. This procedure uses a device called an endoscope, a camera situated at the end of a flexible tube, which is threaded into the stomach through the esophagus. A polymerase chain reaction (PCR) test is often used both to confirm the presence of Helicobacter in a given sample and to differentiate between the species of Helicobacters. However, confirmation can also be done by taking a tissue sample using the endoscope and observing the sample through microscope. 

Note that the presence of gastric Helicobacters in the body do not necessarily indicate an infection that needs to be treated.


As this disease is not fully described in animals, there is no single regimen accepted for treatment. If there are no apparent symptoms treatment is usually not conducted. On the contrary, in humans treatment is started if a Helicobacter infection is found, no matter whether clinical symptoms are present because such an infection can lead to stomach cancer in. However, this does not appear to be the case with cats, so further action is not taken unless the symptoms warrant it. If there is chronic vomiting or inflammation of the gastric lining, treatment will be directed toward easing those symptoms. Typically, fluid therapy will be carried out to compensate for fluid loss. 

Antibiotics, along with acid controlling drugs are the recommended course of treatment for cats found to be infected with a Helicobacter spp. Treatment generally consists of a two week course. Your will need to return to your veterinarian several weeks after the initial treatment for a follow up exam to verify whether the treatment was successful. In many cases, the infection or presence of bacteria returns, but it is not known if this is due to recrudescence (a renewal of the infection after a dormancy), or to reinfection from an outside source.

Living and Management 

Cats that are infected with the Helicobacter bacterium are more vulnerable to stomach upset, so it is suggested that their diet be changed to food that is easily digestible. In addition, if gastritis (inflammation of the gastric lining) is present, your veterinarian can instruct you in conducting an elimination diet so that you are able to avoid the foods that are most disruptive to your cat's digestive tract.

This disease is common where animals are kept in overcrowded and unhygienic conditions. If you keep many animals, be sure to provide them with enough space and a clean environment. Because this bacteria has been found to infect surface water, it is best to try to prevent your animals from drinking from streams, ponds, or rivers.

If you or your cat have been diagnosed with the Helicobacter pylori infection, talk to your veterinarian and your family doctor about the zoonotic potential of this organism and follow the guidelines given by your health care professional.

Image: Alekzandr Kurganov via Shutterstock

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