Have Cat Questions? Ask a Cat Vet Online.
HEllo, this is Dr. JEss. I am sorry to hear about your kitty!
Are his appetite and energy level normal? Are his gums pink in color? Is he having any vomiting? Any changes in diet? Is he in indoor/outdoor cat?
Ok. Has he been on any sort of dewormer or is he on a combination flea preventative/dewormer? The first things we want to be sure of in a cat that has been an outdoor cat is that there aren't any intestinal parasites. You can check this without bringing your cat in because most clinics will let you drop off a stool sample to be tested if they have seen your cat before, so if you are still in the same town as your old vet you could see if you can drop a sample off for testing.
You can go ahead and administer a dewormer to be safe as well, there are some available without a prescription, such as: http://www.petco.com/shop/en/petcostore/cat/cat-health-and-wellness/cat-wormers/sentry-sure-shot-fish-flavored-liquid-de-wormer which will treat roundworms,
but they will not treat other parasites such as coccidia, which can only be treated with a prescription medication. I would also consider a probiotic, which helps replenish the normal healthy bacteria in the GI tract.
I like this product: http://www.amazon.com/ProPectalin-AntiDiarrheal-Gel-Dogs-Cats/dp/B00552J3QU which is a paste that has both probiotics as well as kaolin and pectin which help soothe the GI tract.
You want to avoid any products like pepto bismol because they contain BISMUTH SUBSALICYLATE which can be toxic to cats, so avoid anything OTC with that ingredient.
Feeding a bland easily digestible diet for several days may help as well. A mixture of plain cooked white rice and boiled ground beef or chicken breast- no fats/oils/spices/etc.
If the diarrhea is still persisting, if vomiting occurs, if energy level decreases, if the gums begin to look pale, or if the blood persists in the stool, a veterinary exam is needed because additional testing and prescription medication may be needed.
If you have any other questions, please let me know.. If you do not have any other questions, please take a moment to RATE our conversation so we can know if you were satisfied with your service and I can get credit for helping to answer your question. Thank you and good luck!