Radioactive Iodine Therapy
We have treated over 200 cases of hyperthyroidism in cats with radioactive iodine. This is acknowledged to be the best treatment for this common endocrine disease of old cats. If your cat has been diagnosed with hyperthyroidism simply call and ask one of our veterinarians about this state of the art treatment.
Feline hyperthyroidism is one of the most common treatable diseases of elderly cats in Australia. Canberra Vet Hospital accept referrals for the gold standard treatment of affected cats, radioactive iodine (I131) therapy.
Cats are typically hospitalised with us for 7-10 days and all clients receive written instructions on aftercare which is done at the referring vet’s clinic. We have the facility to treat 2 cases each week, so cats can be referred ASAP.
This section of our website is intended to help pet owners best understand the condition better (including treatment
options), and referring vets to make efficient and effective referrals to our clinic for I131 therapy.
Hyperthyroidism is one of the most common hormonal disorders affecting cats. It typically affects cats older than eight years of age. Affected cats frequently have the peculiar combination of eating a lot more food, while at the same time losing weight. They almost always drink a lot more as well.
If left untreated, affected cats suffer from heart disease, high blood pressure and marked weight loss. The condition is life threatening.
Fortunately a variety of excellent therapies exist from tablets to surgery.
What is hyperthyroidsm?
The thyroid glands are located on either side of the windpipe and produce a hormone called thyroxine. Thyroxine is an important chemical does a great many things in the body but essentially gives you your “get up and go”.
A cat with hyperthyroidism produces way too much of this hormone which has a knock on effect on many areas of the body:
- Blood pressure
- Heart rate
- Metabolic rate
Hyperthyroid cats frequently develop high blood pressure which can cause problems for the heart and kidneys.
Heart disease is one of the biggest problems as the increased amount of thyroxine causes the heart to beat faster and increase in size. Eventually this process (called cardiomyopathy) results in heart failure.
Sustained high blood pressure damages the kidneys. Very often these animals have underlying kidney disease, which may complicate treatment.
These cats are burning energy at a phenomenal rate so become very thin.
What Symptoms Will My Cat Have?
Cats with hyperthyroidism often have a characteristic set of problems you may notice:
- Weight loss
- Ravenous appetite
- Increased thirst
- Using litter tray more frequently to pass large volumes of urine
- Restlessness or hyperactivity
- Vomiting or Diarrhoea
- Fast beating heart (you may feel this on the outside of the chest)
How Do We Diagnose Thyroid Disease?
Thyroid disease is diagnosed on the basis of symptoms and blood tests.
Treatment of Hyperthyroidism
Hyperthyroidism can be managed in three ways:
- Radioactive Iodine Therapy
Tablet therapy can be useful, but you have to be able to give a pill two to three times a day for the rest of your cat’s life to be effective. Although this treatment option spreads the cost of treatment it costs a lot more to use tablets as pets require ongoing blood tests to monitor the success of therapy. Many cats will not toerate the medication as well. So from a hassle and cost perspective this is not always the best option.
2. Surgery to Remove the Affect Glands (Thyroidectomy)
Surgical removal is also possible and often effective way to treat the disease. However there are risks and complications involved in anaesthetising an elderly cat with heart disease (which is frequently the case with hyperthyroid cats).
3. Radioactive Iodine Therapy
This is the best treatment option for cats with an overactive thyroid gland. It is safe, effective in 95% of cases and has few in any side effects. It involves the giving a dose of a mildly radioactive iodine isotope to your cat. At Canberra Veterinary Hospital this is given as an oral capsule.
Because the thyroid gland is the only gland in the body that uses iodine the radioactive particles concentrate within the thyroid gland and the radiation emitted destroys only the overactive thyroid tissue. The rest of the body is unharmed – making it a wonderfully targeted therapy.
Only a small number of facilities offer radioactive iodine treatment in Australia and cats are required to stay hospitalised at our hospital for a few days following treatment.
What is the Long-term Outlook for my cat?
In most cases it is excellent. But the outlook for cats suffering from hyperthyroidism depends very much on the time of diagnosis and whether any other diseases are present. In many cases, if the problem is diagnosed quickly the treatment will cure the problem. The trick is to get your pet checked out by your vet as soon as you see any of the symptoms described above.