Felimazole Cat Thyroid Medication | Petco

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Health & Wellness
My cat takes Felimazole twice daily. Can I give it once a day?
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.
Updated on September 24th, 2025
Vet Q & A
My cat missed a Felimazole dose. Is it okay to give the pill now?
Felimazole is a treatment for feline hyperthyroidism. Missing one dose of this medication usually doesn't significantly affect the blood levels of the drug, so I would expect no negative effects from the missed pill. If you suspect that he's getting to be good at spitting out the pills once you give them (i.e. you find more around the house), talk to your vet about a liquid formulation of this medication, that might be easier for you to give. It also can be formulated as a topical medication that is rubbed inside the ear.
Updated on September 24th, 2025
Vet Q & A
Cat lethargic, not eating on Felimazole. Is the dose too high?
I am sorry to hear about Midnite. I would call and let your vet know of the symptoms. You don't mention if he just started this medication or if he has been on it long term. Some cats can experience lethargy and GI upset when first starting the medication and in some cases we need to start at a lower dose and taper it up, but you need to consult with your vet in order to know if this is the right course of action for your kitty. If he has been on methimazole for a long time and just started with the lethargy/decreased appetite, then an exam and possibly bloodwork are in order for him to ensure there isn't another cause for his symptoms.
Updated on September 24th, 2025
Vet Q & A
What are the best medication options for my cat's hyperthyroidism?
I assume that Chetoh was diagnosed with hyperthyroidism, as cats are rarely diagnosed with hypothyroidism. Typically, I treat with methimazole pills twice daily as a starting point. I find that the T4 hormone is better controlled with oral medications than the transdermal medications on the ear because absorption is variable with this method. Once hyperthyroidism is well controlled and it is apparent that the kidneys are stable, it can be worth considering I-131 (radioactive iodine) treatment, as it stops the need for medication at home in most cases. All of that said, there are still plenty of cases that I do prescribe the transdermal ear version of methimazole because some cats are extremely difficult to medicate at home. Just make sure that Chetoh follows his vet's recommendation for follow up lab testing so that his medication dosage stays appropriate.
Updated on September 24th, 2025
Health & Wellness
My cat on methimazole has side effects. Are they an emergency?
These signs could be consistent with methimazole related side effects. GI upset and facial itching are some of the most common acute side effects in the first few months of therapy. I would recommend stopping the medication until you can talk to your vet about your concerns. Some cats can not take this medication and thus require an alternate method of treatment. If still eating and drinking that is good. If any of the symptoms worsen an ER visit is advised. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!
Updated on September 24th, 2025