What is Hyperthyroidism?
Hyperthyroidism is a common condition in older cats. The thyroids are small glands in the
neck that produce the thyroid hormone, involved in metabolism. In cats, it can often become
overactive. This can lead to various health issues if not treated;
● Increased appetite
● Weight loss
● Increased thirst and urination
● Hyperactivity or restlessness
● Vomiting or diarrhoea
● Unkempt fur or changes in coat condition
● Excessive vocalisation
● Heart issues including rapid heart rate, high blood pressure or further heart disease.
Treatment Options
Fortunately, hyperthyroidism is very treatable with an excellent prognosis. There are several
effective options and we can work with you to find the best option for you or your cat.
● Medical treatment
There are several medication options designed to stabilise the thyroid levels. You can
choose between oral tablets, oral liquid or an ointment on the ear, depending on what you
feel will be easiest to give your cat. Treatment is usually given morning and night.
Once starting treatment, we typically recommend a blood test in 4-6 weeks to reassess the
thyroid levels and adjust the dose depending on the results.
In most cases, medical treatment can be continued lifelong to keep the thyroid levels stable.
Alternatively, radio-iodine treatment or surgery can be considered for a more permanent
treatment, often avoiding the need for long term medications. See below for further details.
● Radio-Iodine Treatment
This is a usually permanent solution. The cat is given a small dose of radioactive iodine,
which targets the overactive thyroid tissue. It requires the patient to stay at a veterinary clinic
for approximately 1 week. It typically has excellent results and often provides long-term cure.
At The Cat Clinic, we have specially designed facilities to be able to offer this treatment to
our patients and referral patients.
There is a wait list, so if you are interested, please let us know so that we can put your cat’s name down.
Please also see further information about radioiodine treatment in our FAQs page.
● Surgery
In some cases we may consider surgical removal of the thyroid gland. It can be effective but
requires general anaesthesia and comes with surgical risks. This may be recommended in a
patient who does not respond well to other treatments, or if there is some concern about
potentially malignant changes to the thyroid gland.
● Prescription diet
In some cases, hyperthyroidism can be managed with a very strict iodine-deficient
prescription diet. To be effective, this does require the cat to eat only this diet, with no other
traces of food or treats. In our experience, this can be difficult to achieve reliably, and so we
do not often recommend this approach.
Monitoring
Regular blood tests are essential to monitor your cat’s thyroid hormone levels and overall
health during treatment. Your veterinarian will recommend how often these tests should be
done, especially after starting treatment or adjusting medication.
We also like to monitor kidney function and blood pressure for cats with thyroid disease, as
these can be related issues.
Conclusion
For further information, see website below;
https://icatcare.org/advice/hyperthyroidism/
Hyperthyroidism in cats is very manageable, and treatment can greatly improve your cat’s
health and quality of life. If you have any questions or concerns, please discuss further with
your veterinarian. Together we can work out a plan that will work well for you and your cat.