Inflammatory bowel disease (IBD) in cats

Content by Dr Emma Chandley BVetMed PGCertSAS MRCVS

Inflammatory bowel disease (IBD) is a long-term inflammatory condition affecting the gastrointestinal tract. In affected cats, inflammatory cells accumulate within the wall of the stomach or intestines, which can interfere with normal digestion and absorption of nutrients. 

The exact cause isn’t fully understood. Current evidence suggests that IBD develops through a complex interaction between the immune system, diet, the bacteria living in the gut and other environmental or genetic factors. Cats of any age can develop IBD, but it’s seen more commonly in middle-aged and older cats.

You may also hear your vet use the term chronic enteropathy. This is a broader term covering several long-term intestinal disorders. Not every cat with chronic digestive symptoms has true IBD, which is why reaching the correct diagnosis can take some investigation.

• IBD causes long-term or recurring inflammation within the digestive tract.
• It’s more commonly diagnosed in middle-aged and older cats.
• Vomiting, diarrhoea and weight loss are common signs.
• Other conditions, including intestinal lymphoma, can cause very similar symptoms.
• Treatment may involve dietary changes, medication or a combination of both.
• Many affected cats can be managed successfully and enjoy a good quality of life.

There isn’t one known cause of feline IBD. It’s thought to develop when the immune system has an abnormal response to substances within the gastrointestinal tract. The normal balance between the intestinal immune system, food and the bacteria living in the gut appears to be an important factor. Genetics may also influence susceptibility, although the exact role these play is still being investigated. Changes in the gut microbiome, dietary factors and other intestinal disease may also play a role.

IBD is usually considered a diagnosis of exclusion. This just means your vet needs to investigate other possible explanations for your cat’s symptoms before concluding that IBD is responsible. Parasites, dietary intolerance, hyperthyroidism, pancreatitis and intestinal cancer can all cause similar digestive problems.

IBD can affect cats of any breed, sex or age. There isn’t a single breed that can be considered particularly prone to feline IBD. Some studies have suggested that certain purebred cats may be overrepresented.

Age appears to be more relevant, with IBD more commonly diagnosed in middle-aged and older cats.

The signs depend partly on which part of the gastrointestinal tract is affected. Some cats have signs relating to the stomach or small intestines, while others have inflammation affecting the large intestine.

Common signs include:

• Vomiting
• Diarrhoea
• Weight loss
• Reduced or changing appetite
• Lethargy
• Poor coat condition
• Blood or mucus in the faeces in some cases

Vomiting and weight loss are particularly common when the stomach or small intestine is involved. Cats with inflammation affecting the large intestine may be more likely to develop diarrhoea, sometimes with blood or mucus.

Not every cat will show all of these signs. Some may continue to eat relatively normally but gradually lose weight, while others become less interested in food. Signs can also fluctuate, with periods when a cat appears relatively well followed by a flare-up of vomiting or diarrhoea.

Because cats are very good at hiding illness, subtle changes can be important. A gradual loss of weight, changes in appetite or repeated vomiting should not simply be assumed to be part of getting older.

Diagnosing IBD can take time because there’s no single test that confirms the condition. Your vet will usually need to investigate several possible causes of your cat’s symptoms. Your vet will start with a detailed history and physical examination. Blood and urine tests may be recommended to look for other illnesses that can cause similar signs. Faecal testing may also be used to investigate intestinal parasites.

Depending on the individual cat, further investigations can include abdominal X-rays or ultrasound. Your vet may also recommend checking levels of vitamin B12 and folate because intestinal disease can interfere with their absorption.

A carefully controlled dietary trial may form part of the investigation. This can help identify cats whose symptoms are related to a dietary sensitivity or respond to nutritional management.

If the diagnosis remains uncertain, your vet may recommend intestinal biopsies. Samples can be collected using endoscopy or during abdominal surgery and examined by a veterinary pathologist. This allows the type and severity of inflammation to be assessed. Biopsy is particularly important in some cats because IBD and intestinal lymphoma can look very similar. Distinguishing between these conditions can be challenging, even when tissue samples have been obtained.

Treatment depends on the severity of the disease and how an individual cat responds.

Dietary management

Diet is often an important part of treatment. Your vet may recommend a carefully controlled diet trial using a novel protein or hydrolysed diet to see whether dietary management improves the digestive signs. These diets are designed to reduce exposure to dietary components that may be contributing to gastrointestinal signs.

For a diet trial to be useful, it needs to be followed very strictly. Treats, table scraps and flavoured medications can potentially interfere with the results. Some cats respond well to dietary management alone, while others need additional treatment.

Medication

Some cats require medication to control intestinal inflammation. Corticosteroids such as prednisolone are commonly used because they have both anti-inflammatory and immunosuppressive effects.

Other medication may be considered where corticosteroids aren’t sufficient or aren’t appropriate. More potent immunosuppressive drugs, such as chlorambucil, may be used in selected cases under veterinary supervision. These medications require appropriate monitoring because they can affect the immune system and blood cell production.

Vitamin B12 supplementation may also be recommended if blood testing shows that a cat is deficient. Other supportive treatments may be used depending on the individual signs.

Different approaches work for different cats. Some respond really well to dietary management, while others require a combination of diet and medication. Treatment may also need to be adjusted over time.

IBD is generally a condition that is managed rather than cured. The good news is that many cats respond well to treatment and can maintain a good quality of life for years.

Symptoms can flare up from time to time, so ongoing monitoring is important. Your vet may need to adjust medication or investigate a change in symptoms, particularly if a previously well-controlled cat begins losing weight or develops recurrent vomiting or diarrhoea.

The long-term outlook varies between cats and depends on the severity of the disease, the response to treatment, and whether there are any other conditions contributing to the gastrointestinal signs.

“In practice, one of the difficult things about feline IBD is that the early signs can be very subtle. A cat may just lose a little weight, vomit occasionally, or become more selective about their food. Because these changes can develop gradually, it isn’t unusual for owners to think their cat is just getting older or becoming a little fussier.

“If I’m concerned about IBD, I would always want to look at the bigger picture rather than focusing on one symptom. A thorough history, examination and appropriate investigations are important because several other conditions can look very similar.”

Dr Emma Chandley BVetMed PGCertSAS MRCVS

If you’re thinking about buying a Petgevity Lifetime Plus policy, we’ll consider all pre-existing conditions when offering cover for your cat* – including IBD.

When you apply for cat insurance, you need to let us know: 

• Which medical conditions they’ve had in the last two years 
• Their health status now

Find out more about Petgevity’s cat insurance for pre-existing conditions.