Inflammatory Bowel Disease in Cats

Did you know that inflammatory bowel disease (IBD) is the commonest cause of sickness and diarrhoea in cats?

Shocking, isn’t it. But then again IBD isn’t a black and white, all-or-nothing condition, but exists on a ‘spectrum’ from mild to severe. For example, since this is a waxing and waning condition, if your cat has regular, intermittent tummy upsets then IBD could be the cause. The symptoms are general, mainly diarrhoea, sometimes with blood and mucus, and sometimes sickness.

But that’s where things stop being simple because IBD can affect any part of the bowel from stomach at the top to the colon at the bottom and all the parts in between. In addition, just to complicate things there is a link with inflammation of the pancreas (another digestive organ) AND the liver. We’re already stacking up a nice list of variables, which include:

• Severity: Mild to severe
• Region: Stomach, intestine, colon – or any combination thereof
• Other organs involved: Possible involvement of the pancreas and / or liver

THEN just when that was beginning to make sense, the symptoms (sickness and / or diarrhoea) are quite general, so your vet has to rule out all other causes of tummy upsets before IBD can be diagnosed.

What is IBD?

The key word here is ‘inflammatory’ and it’s what links all of the variables mentioned above. So a good question to ask is “What causes the inflammation?”

Inflammation is nature’s defence mechanism, because the increased blood supply brings with it white cells to fight infection or remove toxins. Anything that irritates the bowel can trigger inflammation such as:

• Bacterial infections
• Parasites
• Food allergy

The theory is the immune system reacts in an exaggerated way when faced with one of these challenges, and this hyped-up reaction is then difficult to switch off.

When IBD is diagnosed your vet may well try therapy to correct the trigger factors BUT we hit another snag. Unfortunately, the majority if IBD cases are ‘idiopathic’ – meaning no underlying trigger factor is ever found and the IBD is self-generating. As you can imagine, this then makes treatment that bit more difficult.

How is IBD Diagnosed?

Reaching a diagnosis is a long and complex process. Indeed, the final diagnostic step – bowel biopsy – is not without risk, so many vets elect to rule out all other possibilities first. They then will have a discussion with you about the probability of this being IBD and whether to trial appropriate treatment or push right through to a definite answer.

Anyhow, I’m jumping ahead. The tests your vet may run are:

• Faecal Analysis: Testing for parasites and also culturing the faeces to see what bacteria are present and whether they are troublesome or not.
• Screening Blood Tests: This is to check out organ function because conditions such as liver disease can have identical symptoms to IBD.
• Specialised Blood Tests: Ranging from a test for pancreatitis to specialist tests looking at the digestive enzymes in the gut and how healthy the bowel wall is.
• Imaging: Your vet may want to perform an ultrasound scan to get a better view of the gut wall and see if there is any suspicion of bowel cancer.
• Bowel Biopsy: If all the other tests have come back normal or negative, then bowel biopsy is the ultimate tool. The histologist looks at the cells present in the gut wall which allows them to reach a diagnosis.

Complications of diagnosis: The problem with bowel biopsy is the surgeon is operating on unhealthy tissue. The biopsy site is sutured close, but sutures stimulate inflammation. If the gut walls swells still further the stitches can cheese wire through the gut with life-threatening consequences.

The alternative is to harvest samples using an endoscope, but this only gathers a small pinch of tissue and there’s a risk the graspers may not collect a piece that is a true reflection of the wall as a whole, thus giving a false impression of what’s going on.

Treatment of IBD

The conventional therapy is a two-pronged attack of diet change and drugs.

Food Options

Since food allergy is considered a trigger, your vet may suggest feeding a low allergy or even a hypoallergenic diet. The idea is to remove the allergic trigger for inflammation and thus switch the reaction off. This is great in theory but the stumbling block is often that hypoallergenic diets are quite bland, and many cats are fussy eaters and refuse to eat them. And for those cats that do eat the diet, sometimes the response is disappointing.

Alternatively, some cats seem to respond better to high fibre diets. These are prescription foods designed to aid weight loss but ironically, they can also help weight gain by aiding digestion. They contain soluble fibres which are known to nourish enterocytes (the cells lining the gut wall) and condition them. But this is a very different matter from adding bran (an insoluble fibre) to your cat’s diet, so discuss this option with your vet to see if it’s appropriate for your cat.

About BARF

Another controversial option is feeding a BARF or raw food diet. The theory behind this is that cats are carnivores and designed to eat meat, rather than the grains contained in many cat food. However, an interesting point to consider is the cat doesn’t sit nibbling the tiny muscles of a mouse’s thigh to get tiny portions of mouse steak. The cat eats the gut, including the stomach contents, which often contains herbage, grains, and foliage, so their digestive system is geared to cope with a certain amount of grain.

Research BARF and look on the internet or speak to cat guardians whose cats have dramatically improved, and you may be left wondering why vets are so hesitant to recommend this as an option. One of the reasons is that vets have a responsibility to only recommend treatment options (and diet is a treatment) that are scientifically proven to be beneficial.

Now, I’m not saying BARF is harmful but I am saying it hasn’t been put through the rigors of scientific trials where all the short and long term benefits and risks have been fully assessed. There are also other factors such as the crucial importance of getting the calcium and phosphorus ratio correct (weak bones in future years if it’s incorrect), plus the increased risk of bacterial contamination and parasites from raw food, which add to the difficulty of feeding BARF responsibly (I know how much trouble and care BARF enthusiasts go to, so please don’t think I’m having a ‘pop’.)

It’s possible in some cases IBD does improve on BARF in the short term, but what about the long term consequences? In theory, high levels of pure protein gives the kidney much more work to do. So what is the impact on kidney and liver function in future years? The answer is we just don’t know, and so it is irresponsible to recommend a diet, the potential complications of which are unknown. After all, feral cats don’t live as long as our pets and there has to be a reason for this.

However, what this does mean is research into BARF is desperately needed and long overdue because if the benefits are as good as some owners claim then we need to know in order that more cats can benefit.

Hand on heart, I am open-minded about BARF and would love to be able hold it out as a drug-free solution to IBD. But thinking with my head rather than my heart, I am unable to do so. This is because I (and vets as a whole) don’t have the facts backed up by research to say it’s safe and that short term improvement won’t have long term consequences. I would no more recommend an untested drug than an untested diet – which is the degree of seriousness that should be applied to all diets, not just BARF.

Drug Options for Treatment

The drug option is to use anti-inflammatory drugs, of which the corticosteroid prednisolone is most commonly used. This can work well, but it does have side effects which can be as serious as inducing diabetes.

Sometimes adding in an antibiotic called metronidazole can help, as this has an ‘immune modulatory’ effect plus it controls bacterial levels in the bowel. The draw back? It tastes foul and most cats refuse to take it.

If the symptoms are severe then your vet may have to resort to much stronger anti-inflammatories such as chlorambucil and azathioprine (both are chemotherapy agents) but these require careful monitoring for side effects.

In the end, what often happens is a little of this and a little of that added together seem to help. But to end on a positive note, researchers are looking into the use of cat-specific pre-biotics and probiotics to encourage healing gut bacteria that promote a healthy gut wall offering hope for all those cats and their owners suffering the misery of IBD.