Diarrhea, loose or watery stools, is one of the most common reasons cats visit the vet. A single loose stool in an otherwise healthy cat often settles on its own, but diarrhea can also be a sign of infection, parasites, poisoning or illness, and it can quickly lead to dehydration, especially in kittens. Here’s what can cause diarrhea, when it’s an emergency and what you can safely do.
Common Causes of Diarrhea in Cats
- a sudden change of diet, or a new treat;
- food intolerance or allergy, including to cow’s milk: many adult cats are lactose intolerant;
- eating spoiled food, trash or something it shouldn’t;
- intestinal parasites, such as roundworms, Giardia, coccidia or Tritrichomonas (read more about worms in cats);
- viral and bacterial infections, such as feline panleukopenia (a serious, often fatal disease in unvaccinated cats) or Salmonella;
- stress, for example after a move, a stay in a cattery or a new pet;
- medications, such as antibiotics;
- poisoning (read more about poisoning in cats);
- chronic illnesses, such as inflammatory bowel disease, hyperthyroidism, pancreatitis, liver or kidney disease and intestinal cancer, which are more common in older cats.
When to Call the Vet
See a vet urgently if your cat:
- is a young kitten: kittens can become dangerously dehydrated very quickly;
- has diarrhea with a lot of blood, or black, tarry stools;
- is also vomiting repeatedly;
- is lethargic, weak, has pale gums or seems in pain;
- stops eating or drinking;
- may have eaten something toxic;
- has a fever;
- is unvaccinated and has severe diarrhea and vomiting, which can be a sign of panleukopenia;
- is a senior cat or has an existing health condition.
Make an appointment with your vet if:
- the diarrhea lasts more than 24 to 48 hours, even if your cat seems well;
- the diarrhea keeps coming back;
- your cat is losing weight;
- you see worms, mucus or small amounts of blood in the stool. Read more about blood in cat stool.
Your vet may ask for a fresh stool sample to test for parasites and infections. It helps to tell them how long the diarrhea has lasted, how often your cat is going, what the stool looks like and whether anything has changed in your cat’s diet or routine.
What You Can Do at Home
If your adult cat has mild diarrhea but is bright, eating and drinking normally, call your vet for advice. They may suggest:
- making sure fresh water is always available, as diarrhea causes fluid loss;
- feeding small, frequent meals of your cat’s usual food, or a bland, easily digestible diet recommended by your vet, such as a veterinary gastrointestinal diet;
- cutting out treats, table scraps and milk;
- keeping the litter box clean, so you can monitor your cat’s stools.
Don’t give your cat human antidiarrheal medicines, such as loperamide (Imodium) or bismuth (Pepto-Bismol), or any other medicine without your vet’s advice: some can be toxic to cats or hide a serious problem. Don’t withhold food for a long time either: cats that don’t eat for more than a day or two can develop serious liver problems.
Wash your hands after cleaning the litter box, as some causes of diarrhea can spread to people and other pets.
Preventing Diarrhea
- change your cat’s food gradually, over about a week;
- don’t give cow’s milk or table scraps;
- keep trash, toxic plants and chemicals out of reach;
- deworm your cat regularly, as your vet recommends;
- keep your cat’s vaccinations up to date, especially against panleukopenia;
- scoop the litter box daily and keep food bowls clean;
- reduce stress during changes, such as moving house. Read more: how to calm a stressed cat.
