Ask the Vet: Treatment Options for Feline Hyperthyroidism

The prognosis is grave: Only a small percentage of cats with saddle thromboembolism survive. (Suphaksorn Thongwongboot/Shutterstock)

Q: Codi, our 13-year-old cat, needs methimazole for his hyperthyroidism, but he won’t take it. I’ve tried crushing his quarter-tablet and mixing it with pilling treats and various wet foods mixed with a flavor enhancer, but nothing works. I’m at my wit’s end trying to get him to take his medicine. Any suggestions are welcome.

A: Hyperthyroidism, the most prevalent hormone imbalance in cats, becomes more common as cats age. Overactive thyroid glands produce excessive thyroid hormone, which revs up the metabolism, causing weight loss despite heightened appetite, as well as vomiting, diarrhea, increased drinking and urination, and behavior changes.

Fortunately, many treatment options are available.

You are giving Codi the generic version of methimazole, which suppresses thyroid hormone production. The drug is also available as Felimazole, a small, smooth tablet that’s easy for cats to swallow.

A pharmacist can compound methimazole into an oral liquid that tastes like fish, chicken, or whatever Codi’s favorite flavor is. Or, the compounding pharmacist can make a methimazole transdermal gel that you'll rub onto Codi’s ear, where the medication will be absorbed into his blood.

An alternative to medication is Hill’s y/d, a diet that limits the iodine necessary to produce thyroid hormone. The food is available in dry and canned forms. You can even make treats from y/d.

The definitive treatment for feline hyperthyroidism is radioactive iodine therapy, which destroys the thyroid tissue responsible for excessive hormone production. Neither methimazole nor y/d is needed after treatment.

Surgical removal of the affected thyroid gland(s) is yet another treatment option.

Since Codi resists taking his pills, talk with your veterinarian about one of the other treatment options.

Q: Our dog, Cooper, stayed at a boarding kennel over the holidays. He was fully vaccinated to protect him from kennel cough and canine influenza, but he still came home with a cough. His veterinarian diagnosed kennel cough and prescribed an antibiotic, and Cooper is improving. But why did he get sick?

A: Most likely, Cooper was sickened by one of the germs against which he wasn’t vaccinated. That’s not your veterinarian’s fault, because vaccines are available for only some of the viruses and bacteria that cause kennel cough, also called infectious tracheobronchitis or canine infectious respiratory disease complex.

It sounds like Cooper was protected from the most common causes of kennel cough: Bordetella bacteria, two strains of the influenza virus, and three viruses usually included in the distemper combination vaccine, including distemper, parainfluenza. and adenovirus.

However, kennel cough can be triggered by other respiratory pathogens for which vaccines are not available, including the herpes virus, respiratory coronavirus, pantropic coronavirus, pneumovirus, reovirus, and multiple strains of Mycoplasma and Streptococcus bacteria.

Also, if Cooper was vaccinated at the start of boarding, he may not have been fully protected. Immunity develops about two weeks after vaccination, so dogs are protected only if they are vaccinated at least that long before boarding.

Moreover, stress suppresses the immune system, so Cooper may have become ill because he was especially stressed while away from home. If he was barking at the kennel, his throat irritation likely worsened his cough.

If Cooper develops kennel cough the next time he’s boarded, consider hiring a pet sitter to stay with him in your home while you are away.

Lee Pickett, VMD, practices companion animal medicine in North Carolina. Contact her at AskTheVet.pet. Copyright 2021 Lee Pickett, VMD. Distributed by Creators.com