Tapazole for Cats

Here comes my thyroid medication.
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If your kitty's been diagnosed with hyperthyroidism, it's possible your vet will prescribe Tapazole as part of his treatment. Your cat will likely take this medication for the rest of his life. Though it helps kitty tremendously, you must take basic precautions when giving it to him.


The thyroid gland regulates the body's metabolism. If your cat suffers from hyperthyroidism, or excess amounts of the hormone, everything goes out of whack. Symptoms of hyperthyroidism in cats include weight loss, diarrhea and vomiting, frequent drinking and peeing, increased heart rate and generally looking ratty. Your cat might lack appetite or always seem hungry. Since hyperthyroidism usually occurs in older cats, some people might think these symptoms are just natural signs of aging, but that's not true. Your vet can diagnose hyperthyroidism through blood tests.


Tapazole is the brand name of methimazole, a drug developed for people but used to treat feline hyperthyroidism. It's often prescribed for cats under the name Felimazole. The medication manages but doesn't cure the condition. Currently the drug of choice for feline hyperthyroidism, Tapazole produces fewer side effects in cats than previous thyroid medications. When your cat initially starts the drug, he'll be closely monitored for a few months by your vet and needs hormone and blood tests to make sure the drug works properly and the dosage is correct. After stabilization, you'll have to bring kitty to the vet at least semi-annually for blood testing.


Tapazole tastes pretty bad, so giving it to kitty might not be easy. You can try mixing it in with food, but that trick doesn't work as well with cats as it does with dogs. Besides the oral version, Tapazole is also available as a gel to rub on the inside of your cat's ear.

Side Effects

Most cats tolerate Tapazole pretty well, but certain side effects are possible. These include depression, vomiting and appetite loss. If your cat exhibits any of these problems, adjusting the amount of medication might solve the problem. Tell your vet about any side effects in your cat so she can make decisions about changing either the medication or the dose.


If you're pregnant or breast-feeding, you should find someone else to give Tapazole to your cat or discuss the issue with your vet. Always wear gloves when applying the gel or when crushing pills to mix in the food. Also wear gloves when cleaning kitty's litter box if he's on the medication or wiping up vomit if he throws up. Your own thyroid might be affected by exposure to the drug.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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