The early stages
Hyperthyroidism is more often seen in older cats.
Recognising the signs of Hyperthyroidism
Typically, you will notice that your cat is suffering from severe weight loss whilst maintaining a ravenous appetite.
Cats with hyperthyroidism produce thyroid hormones in excess, which leads to a dramatic increase in their metabolic rate.
Other common signs to look for include:
- Increased restlessness and irritability
- An unkempt coat
- Diarrhoea
- Occasional vomiting
- Frequent urination
- Increased fluid intake
- Anxious facial expression
- Rapid heart rate
Not all cats will react to the disease in the same way and your cat may not necessarily display all of these signs. Wherever possible, it is always a good idea to keep a note of the changes you see in your cat's habits, behaviour and appearance. When hyperthyroidism is suspected, diagnosis is normally very straightforward.
Physical examination
In most cases, your veterinary surgeon will be able to feel the enlarged thyroid lobes in your cat's neck. Occasionally, the thyroid gland cannot be easily felt. This happens when the thyroid tissue is located elsewhere, usually inside your cat's chest.
Diagnostic tests
To confirm the diagnosis, your veterinary surgeon will arrange a blood test in order to measure levels of the T4 hormone. Although both the T3 and T4 hormones are produced in excess in a cat suffering from hyperthyroidism, total T4 measurement is the most accurate test available.
Since most cats with hyperthyroidism are older, it is recommended that your cat has other blood tests to assess their organ function and make sure that they do not suffer from any other problems. This is important because other conditions might affect the successful treatment of hyperthyroidism.