Inflammatory Bowel Disease in Cats: The On-and-Off Tummy Trouble

Inflammatory bowel disease in cats has a signature rhythm. If your older cat throws up or has diarrhea for a few days, seems fine for a few weeks, then does it all again, inflammatory bowel disease is one of the first things a vet will think of. IBD is one of the most common reasons an aging cat's gut keeps acting up, and it comes with a hard twist, the question of IBD vs lymphoma in cats, because it looks almost exactly like that intestinal cancer, and only a biopsy tells them apart. Once it is pinned down, though, IBD is usually manageable, and many cats do well for years on the right diet and medication.

This explains what IBD in cats is, its symptoms, why its signs come and go, how it is told apart from lymphoma, and how it is treated. What is actually going on in your own cat's gut is a question for your vet, not a guess from a list of symptoms.

What is IBD in a cat?

Inflammatory bowel disease is less a single illness than a state the gut gets stuck in. Cornell describes it as a condition in which a cat's gastrointestinal (GI) tract becomes chronically irritated and inflamed. It can strike a cat at any age, but it is a problem of later life above all: as Cornell notes, cats of any age can be affected by IBD, but the disease occurs most often in middle-aged and older cats. Why it happens is not fully understood. Cornell puts it honestly: while the cause of IBD is unknown, current evidence suggests that it arises from a complex abnormal interaction between the immune system, diet, bacterial populations in the intestines, and other environmental factors.

The signs, and why they come and go

Where the inflammation sits decides what you see. VCA lays it out simply: if the stomach is involved, your cat will experience chronic vomiting, and if the intestines are involved, your cat will have chronic diarrhea. Cornell's fuller list of vomiting, weight loss, diarrhea, bloody stools, lethargy, and decreased appetite covers most of it. What confuses owners is the rhythm: the signs tend to flare for a few days, settle for a week or two, then return, so it is easy to dismiss each bout as a one-off. Weight is the quiet giveaway. VCA notes that if the syndrome lasts for more than a few months, poor appetite and weight loss are common, and, counterintuitively, in some cases, cats develop a voracious appetite because they are unable to absorb the food they are eating. A cat with recurring vomiting or diarrhea who is slowly losing weight is the classic picture.

IBD or lymphoma?

This is the question that makes IBD more than a nuisance. Its signs overlap almost perfectly with intestinal lymphoma, the most common feline cancer, and the two are genuinely hard to separate. Cornell is direct: intestinal lymphoma, a form of cancer, can be particularly difficult to distinguish from IBD in cats. There is also a thread connecting them, since VCA notes that some forms of inflammatory bowel disease may progress to intestinal cancer. That is the real reason not to keep shrugging off a cat's on-and-off stomach trouble: sorting benign inflammation from lymphoma is exactly what your vet needs to do, and it is worth doing while there is the most to be done.

How is IBD diagnosed and treated?

Because so many things cause a chronically upset gut, IBD is partly a diagnosis of exclusion, and confirming it takes more than bloodwork. Cornell is clear that a definitive diagnosis of feline IBD requires an intestinal or gastric biopsy and evaluation of the tissue under a microscope, which is also how the same sample rules cancer in or out. Treatment then runs on two tracks. The first is food. Cornell notes your vet may recommend a food trial using hypoallergenic diets, and VCA stresses that this is not a casual swap: a true food trial requires that the test diet be fed exclusively for 8 to 12 weeks, which means no treats or table scraps for the duration. The second is calming the inflammation. Cornell notes that corticosteroids, which are potent anti-inflammatory and immune-suppressing agents, may be recommended, either alone or in combination with metronidazole. Getting a diet right and giving daily medication both take patience, and the payoff is a cat who eats well and holds her weight. Owners often ask about adding a probiotic alongside all this, and it is worth reading what the evidence actually supports first, particularly the caution about cats on immune-suppressing medication.

When to see the vet

Book a visit for any pattern of vomiting or diarrhea that keeps coming back over weeks, especially if your cat is also losing weight, and do not wait for it to become constant. The come-and-go rhythm is the trap: because she seems fine between bouts, it is easy to let months slide by, and that is time you may not want to lose if the cause turns out to be more than inflammation.

Biscuit's stomach has always been the sensitive sort, so I have learned to log the bad days rather than trust my memory of them. It is a dull little habit, a note on the calendar each time. Inflammatory bowel disease in cats hides in that scattering of "off" days, and a simple record is exactly what a vet wants to reveal it as a pattern worth chasing down.

Sources

• Cornell Feline Health Center, Inflammatory Bowel Disease
• VCA Animal Hospitals, Inflammatory Bowel Disease in Cats