My cat got a double dose of Comfortis. Should I worry about an overdose?

Poor Clair! The Comfortis tablet often dissolves quite quickly, but Elanco reps have said that if a cat vomits within an hour of medication administration, the cat should receive another dose. To confirm this information and to report Clair's vomiting, I recommend calling the phone number on the Comfortis packaging.

Thanks for using Petco Pet Education Center, formerly Petcoach! You are correct- Cody will need the 560mg size. It won’t hurt to give the smaller size but it may not be totally effective. Or you can contact your veterinarian and see if you can switch out the dose for the correct size. Good luck and kisses to Cody!

Great question and thank for you for providing the pictures! It is not safe to give your cat the Comfortis in a box that only has a picture of a dog on it. That medication is for dogs only. The box that has both the cat and dog on it means that it is safe to give to cats, and be sure to give your cat the dose according to his weight. I hope this helps :-)

Hello. According to the manufacturer, cats as young as 5.5 weeks tolerated doses of 5x labeled dose every 14 days. For your kitten, you are just about there. But it really takes a massive overdose to start to get concerned. But do watch for signs of overdose including salivation, vomiting & depression. If you see any of these signs in the next hour or so, & they do not clear up within a few hours, or the kitten really seems significantly affected, do seek veterinary attention. Hopefully, the kitten will be just fine by tomorrow. Thanks for contacting Petco Pet Education Center, formerly Petcoach.

Unfortunately, this could be serious. As I'm sure you know, this is an extended release product, and the typical dose is 100mg per cat every 24 hours, so yes, I believe you very well might see toxicity from this, including (on the mild side) excitement, hyperactivity, vomiting, and diarrhea, all the way up to seizures. You have a couple of options: you can call the ASPCA's toxin hotline at (888) 426-4435; they will charge you for the call ($45) but they keep an extensive database on all types of overdoses and will be able to tell you if this is a significant overdose. Your other option is to take Nox to an emergency clinic now to have vomiting induced, and have him treated for the ingestion. They will be able to administer activated charcoal to absorb any residual toxins in the gut as well.

With your cat's weight being 11 pounds, there is a dose range for Buprenorphine that fits into the amount you gave. He may be a little sleepier and I would not continue the double dose unless your vet recommends it. Keep an eye on him in case he is too sleepy, but he should be ok. Signs of a problem would be too sleepy, a slower breathing rate.

This medication contains a combination of Spinosad and Milbemycin. Milbemycin can be used safely in dogs for heartworm prevention but has other uses as well, and can be given at a dose two to four times the normal dose that we use for heartworm prevention, so I would not worry at all about a higher then normal dose of that medication. Spinosad is used for flea prevention and is a relatively safe drug. The most common side effects seen with its use include a decreased appetite, vomiting, diarrhea, lethargy and rarely, in dogs with a low seizure threshold, possible seizures. Studies on research dogs showed no long term effects on dogs that were given TEN times the recommended dose. Side effects that were seen at that high dose included nausea, vomiting, a decrease in appetite and some diarrhea. She will probably be OK but all you can do at this stage is monitor her for any signs of toxicity. If any are noticed she needs to see a vet immediately.