My 13-year-old cat has diarrhea. When to worry and how to help?

Poor Sushi! The diarrhea could be due to many conditions including the new diet, bacterial over growth, parasites or even organ disease. If the diarrhea has continued beyond 24 hours, I recommend to have her examined by the veterinarian. With continued diarrhea, there are often bacterial shifts in the gut that will make matters worse regardless of the initial cause. Make sure to bring in a sample of fresh stool. The doctor will check her for parasites and bacterial over growth. Many times a bland diet can help and then a slow, gradual introduction to the normal food can be done. A bland diet can consist of 25% boiled white meat chicken and 75% boiled white rice. This should all be plain. I hope Sushi starts feeling better quickly! Please feel free to post any additional questions.

Diarrhea and a decrease in appetite could be a sign of a number of different problems. Intestinal parasites are possible, even for indoor cats, as are some infections or diseases like colitis or inflammatory bowel disease. If the diarrhea continues for more than 24 hours or seems to be getting worse, or if her appetite does not improve during that time I'd recommend seeing your veterinarian. They may treat her symptoms or recommend some testing like blood work or a fecal analysis depending on what they find during a physical examination.

Withhold food for so long in such a small kitten is not recommended. Diarrhea is a signs referring to a intestinal problem. It could be due to parasitic infestation (very common in kittens) dietary indiscretion, inflammatory disease, bacterial diseases or viral diseases. You could provide bland food (boiled breast chicken or white fish or gastrointestinal commercial diet) for a 24-36 but, if she continues to have diarrhea, might get dehydrated and therefore need to be checked by a veterinarian. Also if you can spot blood in the faces or if she get lethargic and not eating, or if she start vomiting, I would suggest to have her checked by your veterinarian as soon as possible. 
Good luck and post again on the forum if you need further advices. I hope my answer was helpful.

It sounds like your cat has a severe case of colitis, or an inflammation of the colon. This condition causes diarrhea. Colitis can be caused by many different things. Some of the more common causes include intestinal parasites, dietary indiscretion, food intolerance, irritable bowel disease, pancreatitis, a foreign body/blockage and viruses. Food intolerances/allergies can start at any age. This is why it may only now be affecting Ella when she has been eating the same food for a long time. If the diarrhea is server you may want to consider taking Ella to the vet. She may need fluids to correct any dehydration, a fecal examination performed and antibiotics and/or probiotics to help the diarrhea clear up. There are specific prescription diets that your vet can recommend to help with this type of issue. Two I commonly recommend are Hill's i/d and Royal Canin GI low fat. A hydrolyzed protein diet may also be helpful. If you want to try an over the counter food first I would recommend something that is labeled as "limited ingredient" or for "sensitive stomachs". I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

Diarrhea is a common problem with cats and is usually self-limiting (will go away on its own). Usually it's not serious, but it's always possible that it could be the start of something serious. If she has any of the following, then she should see a vet: 1) Blood in diarrhea 2) Very watery diarrhea 3) Starts acting very depressed 4) Stops eating or drinking for longer than 24 hours. 5) Diarrhea lasts longer than three days. You can help her get through this by feeding bland food (i.e. boneless cooked chicken). Feed small portions (1/4 cup or less) at meal time. You can also add probiotics to the food (can get this at the pet store), which has demonstrated some efficacy for improving diarrhea. Ensure fresh, clean water is always available. I hope this helps and Sphynxy gets better soon.

Poor Shadow! I am sorry to hear that he is not feeling well. Until you can get Shadow to the vet (which I definitely recommend) you can with hold food for 12- 24hrs, then offer a bland diet of plain boiled chicken and rice (he may only be interested in the chicken) for about 1 - 2 days. After which you can reintroduce his regular diet. You also want to make sure that both litter boxes are extra clean. Sometimes in multi-cat households one cat decides that he/she no longer is ok using a "used" litter box (cats are wonderful, but have odd behaviors sometimes). It may be worth just keeping them separate so that Shadow has his own personal kitty bathroom until he sees the vet. As I stated earlier, I definitely recommend having Shadow seen by a vet as soon as possible because chronic diarrhea results in dehydration, which in a very small, young kitten we want to address sooner rather than later to prevent progressive potentially severe illness. I hope that this was helpful for you and that Shadow starts to feel better soon!

Poor Lilli! The diarrhea could be due to many conditions including a viral infection, bacterial over growth, parasites or other even organ disease. I recommend to have her examined by the veterinarian. With severe diarrhea, there are often bacterial shifts in the gut that will make matters worse regardless of the initial cause. Make sure to bring in a sample of fresh stool. The doctor will check her for parasites and bacterial over growth. Additionally, the veterinarian can provide medications for symptomatic treatment. Many times a bland diet can help and then a slow, gradual introduction to the regular food can be done. A good diet in general is Royal Canin. It is low residue and highly digestible. I hope Lilli starts feeling better quickly! Please feel free to post any additional questions!