“No, Radioactive Iodine Therapy Will NOT Make Your Cat Glow In the Dark…”

I had to laugh as I answered my client’s child’s innocent question.  But it certainly wasn’t the first time a cat owner had expressed surprise and concern when I first mentioned this treatment for feline hyperthyroidism (see my previous blog for more information on hyperthyroidism).  Radioactive Iodine Therapy (RAIT) certainly does sound scary and this has resulted in some strange misconceptions, but actually it is a fantastic option for the treatment of what can be a frustrating long-term disease of older cats.

What is Radioactive Iodine Therapy?

It’s an increasingly popular treatment for hyperthyroidism (overactive thyroid gland) in cats.  It works because the thyroid gland is the only place in the body that uses iodine, so it all concentrates there.  Iodine that has been made radioactive is injected into the cat and finds its way to the thyroid gland, effectively shutting it down without hurting any other organs.  The radioactive iodine (also known as I-131) is then excreted from the body over the next few weeks.  The urine and faeces of a treated cat are therefore considered radioactive and need to be managed accordingly, which includes a stay in the hospital.  Because of the obvious health and safety concerns, this treatment is only offered at a few places in the UK with special facilities, your vet can give you more information about where your cat could receive this treatment.

What are the benefits of this treatment?

• It is practically painless and very safe for the cat.  Over 95% of the time it only takes a single subcutaneous (under the skin) injection, which is no more traumatic than an ordinary vaccine!  The cat is not otherwise affected by the radiation, it is merely for human health and safety that they must be kept in hospital.  No anaesthetic is required (unlike surgery to remove the affected glands), although occasionally some sedation may be given if the cat is particularly grumpy.  Side effects are minimal and mild, and thousands of cats have been treated successfully without any problems at all.
• It’s easy, and offers a complete cure for the disease.  No more tablets and a lot fewer blood tests, and peace of mind knowing that your cat won’t ever have to suffer the symptoms of the disease again.  He’ll definitely thank you for that!
• It’s usually the most effective form of treatment.  Other options currently available include daily tablets or surgery to remove the thyroid gland.  Tablets merely mask the problem because as soon as the tablets are stopped, the symptoms return and the gland continues to grow despite treatment often requiring higher and higher doses of medication.  Surgery does remove the affected gland, but there is a risk that you may damage the delicate parathyroid glands at the same time.  Also, two surgeries are sometimes needed to remove both glands, and that means two anaesthetics and twice the cost.  Occasionally the thyroid tissue is located in a place that can’t be reached surgically, which is not a problem when radiation is used.

What are the disadvantages of this treatment?

• It is quite expensive, around £1000-1500 for the whole treatment.  However, this needs to be measured against the cost of other forms of treatment, which can be nearly as or even more expensive in the long run.  Also, many pet insurance companies do cover this treatment, so be sure to ask!
• Treated cats have to stay in a cage at the special facility until their radiation drops to a safe level for humans.  This can be a concern for both cats and their owners, as sometimes the hospital stay can last up to 2-4 weeks (much shorter in the US and other countries where the human health and safety rules are not so strict).  It is not much different from putting your cat in the cattery whilst you go on holiday, though the accommodation may not be as posh!  Most cats tolerate this time without issue, it is their concerned owners who find it to be more of a problem.
• Cats must be suitable candidates for treatment.  This means that they cannot have certain other medical problems such as kidney disease or diabetes, and they must be friendly enough to be handled by the hospital staff.
• There is often a waiting list for treatment, as only a few facilities are licensed to perform radioactive iodine therapy in the UK.  You may have to wait several months for treatment.
• A few special precautions may need to be taken after your cat returns home, such as washing your hands after handling your cat and avoiding prolonged contact, disposing of your cat’s litter properly, and limiting access to pregnant women.  But these only last a few weeks at most, then life can return to normal.

All in all, Radioactive Iodine Therapy is a fantastic option for hyperthyroid cats of any age, particularly older cats who may not tolerate anaesthesia well or any cat that hates tablets (which, let’s face it, is most of them!).  If you think this might be the right option for your cat, please do speak with your vet as it must be arranged as a referral from your regular veterinary surgeon.  I’ve had two of my own cats go through the procedure, and all three of us have been very pleased with the results.  And I can personally guarantee that neither of them glow in the dark!