Updated On September 23rd, 2025
Pet's info: Cat | Mixed Breed | Female | spayed | 9 lbs
My cat has been prescribed 2.5 mg of Felimazole twice daily for hyperthyroidism. How long does the Felimazole stay active in the cat’s bloodstream? The reason for the question is that when I need to be away from, I have a cat sitter that comes in once a day to tend to the cat. Should she double the dose (5 mg), or stay with a single 2.5 mg pill?
1 Answer
Published on May 3rd, 2018
Hello. Felamizole generally stays in the system for 12 hours, but it is not uncommon to increase the dose when an owner will be away temporarily. It is best to start the 5mg once a day several days before you leave to see if you notice any difference in Mia, but I have recommended this in the past. Resume the twice daily 2.5 mg dose once you get home. Thanks for using Petco Pet Education Center, formerly Petcoach.
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