Written by Dr Mirjam van der Wel, Principal Veterinarian at Vets Incorporated, Westering
Hyperthyroidism refers to an overactive thyroid gland.
It’s a fairly common hormonal disorder seen in older cats, typically affecting felines over the age of 10.
You’ll likely notice one or several of the following symptoms:
-
Your cat is losing weight despite a (very) good appetite.
-
Your feline is seen drinking (and peeing) more.
-
Its coat can look a bit unkempt, greasy and tatty.
-
Your cat is very vocal (also demanding food!) and doesn’t get settled.
-
Vomiting, diarrhoea, increased heart rate and a bit more effort with breathing can also be noted.
These symptoms are not all specific for hyperthyroidism, so it’s important to consult your veterinarian if your cat shows any of these signs.
Diagnosis typically involves:
-
a physical exam, where your vet may feel an enlarged thyroid gland in your cat’s neck, followed by blood tests that check for elevated levels of thyroid hormones.
Additional tests may be recommended to assess your cat’s overall health and rule out other conditions.
Hyperthyroidism is caused by an overproduction of thyroid hormones (T3 and T4) by the thyroid glands, which are located in your cat’s neck. These hormones play a crucial role in regulating metabolism, so when there’s too much, a cat’s body starts running in overdrive (losing weight despite eating and drinking lots).
In most cases, hyperthyroidism is caused by a benign (non-cancerous) tumour called an adenoma on the thyroid gland. Though the tumour itself isn’t usually dangerous, the hormonal imbalance it causes can lead to serious health complications, including high blood pressure, heart disease, and kidney problems.
The good news is that hyperthyroidism can be well managed, especially if it’s been caught early.
-
Treatment usually involves daily medication or the use of a transdermal gel.
-
Some patients can be managed on an iodine-restricted diet only.
-
While surgery is sometimes an option, usually other methods are preferable.
-
And, in some countries (not South Africa at this stage), radioactive iodine treatment is available
Your vet and you will decide what’s suitable for your feline.
So please remember, if your cat is over the age of 10, regular wellness check-ups are essential.
Routine bloodwork can catch hyperthyroidism early – even before symptoms appear.
If you notice changes in your cat’s behaviour, weight, or appetite, don’t wait – schedule a visit with your veterinarian. Early diagnosis and treatment can make all the difference in your cat’s health and quality of life.
