Kitten threw up after dewormer or tuna. Should I call the vet?

If he vomited within 2 hours, I would recommend calling your vet to let them know and picking up a second dose to repeat the treatment. It likely didn't have enough time to absorb in to Allyson's system.

Thank toy for submitting your question regarding Dusty. I would contact her veterinarian in the morning to let them know of the vomiting. It is likely due to the deworming medication. It can sometimes cause vomiting as the parasites are being killed. They may send her home with an anti-nausea medication if this is the case. This medication can typically given as an injection by the veterinarian and then tablets to continue at home. I hope this information helps!

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.

Thank you for submitting your question regarding your kitten. If he is not improving, then I recommend that he has a further work up. He should have fecal testing, blood work and x-rays of his abdomen to determine the cause of his vomiting and inappetance. Kittens can react to deworming medication, but it is typically a short lived reaction. It worries me that he is still ill. There is likely another another disease process present. In the meantime, encourage him to drink so that he does not become dehydrated. I hope this information helps!

It is possible that the worms were the reason why he wasn't eating, and the deworming treatment itself can make him feel nauseous and unwell. It's the result of the dead worms moving through his GI system. I would recommend offering him a bland diet of boiled white meat chicken (no bones) in small amounts to try to tempt him to eat. You can also soak his dry food in tuna juice, or offer him gently warmed really smelly wet food, such as sardine or fish based. If he still isn't eating in the morning, I would have him seen by the vet again. It will take at least two deworming treatments to kill all the worms.

Deworming doesn't directly stop vomiting. IF the vomiting is indeed caused by the intestinal worms, I would expect vomiting to stop within a week or so of deworming, but it could be longer if the parasite load was causing a lot of irritation. I would still recommend a recheck if still vomiting after 5-7 days.

It's actually pretty serious when a cat won't eat anything as if they go long enough without eating, they will develop a fatty liver. Because Toby is still vomiting and not eating, it's time to see a vet immediately. Please take him into an ER vet now. If there isn't one in your area, there will be a vet on call for emergencies. The information to find that vet is found on a clinic's answering machine or website. Best of luck.