Thyroid Disease in Cats
Published by Veterinarian Elaine McIlhinney
I had the pleasure of meeting Jill and her shy cat Marmite at a routine health check and vaccination appointment last year. Marmite had dropped a large amount of weight in the previous months, had been eating ravenously and frequenting her water bowl. Jill had noticed that she was also having bouts of vomiting and diarrhoea. On examination she had an enlarged thyroid gland in her neck and a fast heart rate. The diagnosis of an overactive thyroid (hyperthyroidism) was confirmed by a simple blood test that I ran in the clinic.
Thryoid disease is a common condition of older cats usually secondary to a benign tumour of one of the thyroid glands. The hallmark of this disease is weight loss in the presence of a ravenous appetite. Some cats will not show all the classic symptoms and we find the occasional cat can present unwell and not eating. Diagnosis in these cases can be tricky as with illness sometimes the thyroid level can actually decrease even in the presence of this disease.
The good news this is often a simple and rewarding condition to treat. There are several treatment options.
The gold standard treatment is radioactive iodine treatment. Cats that are otherwise well are great candidates for this. Treatment involves a 1 week hospital stay at VSG in Auckland, followed by 2 weeks of reduced physical contact with their owner ie. no cuddles and no sleeping on the bed (which can be tricky for some of our kitties and their owners!) In most cases this is curative but there is a 15% chance that the other thyroid gland can succumb to the same illness after a couple of years.
Other treatment options include a daily tablet or absorbable gel that is applied to the inner ear flap once daily.
For those cats that will not tolerate medications, 'Hills' pet food produce a food that is iodine free called 'Hills y/d'. This starves the thyroid gland of iodine so it cannot produce the thyroid hormone. This can be a good option for cats who have kidney and thyroid disease.
Lastly there is the option of surgery. The affected lobe of the thyroid gland is removed under general anaesthetic. Because the thyroid gland is in close proximity to the parathyroid gland, calcium levels need to be carefully monitored after surgery. Because radioactive iodine is the safest option now a days, surgery is less commonly performed here at Mill Road.
If you think that your cat could be suffering from Thyroid disease, please get in touch with one of our friendly receptionists to make an appointment!