• I just had an appointment with the vet because my cat is allergic to fleas. She was given a shot for the allergies and some steroids to alleviate the itchiness. I gave my cat the Comfortis Feline Orange tablet (1 month dose of flea prevention) around 3:00 pm and she ate it with her food. However, 2 to 3 hours later, she vomited. I don't know if she vomited due to the medication or because she was too hungry after spending the day at the clinic and ate more than usual or because she has been licking herself more due to her irritated skin and ingested more hair than usual. I've read is a common side effect for pets to vomit but do I need to give her another tablet or was that time enough for the medicine to be effective? How can I get a flea prevention prescription? This treatment seems to be better but I can't purchase it without a prescription. Thanks for your assistance!

    Hi Stephanie,

    I recommend that you call and talk to your local veterinarian about these questions. Comfortis can cause vomiting but it is usually seen within an hour after giving the pill. The vomiting may be a combination of the medication and stress. If she has continued to vomit I recommend that you take her into see a vet. If it was just the one time it is likely not anything to worry about. Usually there is no need to re-dose the medication after about an hour but this can depend on the individual pet and if any of the medication was present in the vomit. Your vet can give you the best recommendation on if she needs another dose. Your vet will also be able to provide you with a prescription for the Comfortis.

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