My cat is lethargic and quiet after deworming. Should I worry?

Some kittens will become lethargic if there is a high worm burden in their intestines. The sudden death of a large number of worms can slow things down in their GI tract and cause discomfort. If she goes longer than 24 hours without food, or is seen having vomiting or diarrhea, then Tessa should be re-evaluated by your vet.

I am concerned as well. While a kitten can have some lethargy after receiving vaccines and deworming treatments, it's not normal for that to last more than a day or two. If she is eating and drinking normally, then you can wait until the morning to have her seen by a vet by a health check. Should she not be eating or drinking normally, then I would have her seen by an ER vet tonight.

It sounds like there could be an underlying issue. Tapeworms don't usually cause coughing and lethargy in cats. Your cat should be examined by a vet to determine the exact cause and treat the problem. Your vet can run labwork and take an xray, if needed, to help diagnose and then determine the best way to treat.

He needs to be seen by a veterinarian for a wellness exam. He may not be able to poop and may be constipated, or he had so many worms that all the dead worms are making him ill. Keep him warm, entice him to drink water, and should he deteriorate he needs to be seen at a petER tonight.

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! I have seen deworming pills cause an upset tummy: vomit, diarrhea, decreased appetite. It usually resolves in 1-2 days. The pill may not be the cause of why Lucy isn't acting normal. If it has been 2 days since you gave the pill I would have Lucy seen by your Vet to make sure she is ok. I hope this helps and I wish Lucy the best!

Poor Frodo! Some cats do vomit during deworming due to the strength of the medication combined with the parasites moving through the GI system. These side effects should only last a few days, so if it's been longer than that, I would be concerned that it could be due to something else, such as a GI illness, a foreign body, or pancreatitis. I recommend withholding food for 12 hours, then feeding a bland diet of boiled white meat chicken (no bones) in small amounts several times a day for a couple of days. Then slowly add back in his normal diet. If the vomiting continues in the absence of food, he vomits the bland diet, develops diarrhea, stops drinking water, starts vomiting water, or becomes very lethargic, he will need to see a vet right away.

Poor Garfield! Tapeworms do not usually cause any significant weight loss or other symptoms in cats, so I would be very concerned that Garfield has a more serious problem. I would recommend taking him to the vet for an exam when you are able to. He/she can do some diagnostic testing (blood work and x-rays) if needed to help determine what's wrong, and will get him started on appropriate treatment depending on what is found.