Thyroid Problems In Cats

Thyroid Problems In Cats

Cats and Humans share a number of different diseases and conditions. One of these which can be fatal without treatment involves problems with the Thyroid gland.

The Thyroid Gland

This small gland located in the neck in both Cats and Humans controls the production of hormones which regulate metabolic rate, heart, muscle control and brain development plus a whole host of other things. It's fair to say correct function of the Thyroid gland is pretty important to health of both your cat and to you!

The Thyroid gland depends on a sufficient supply of Iodine from diet in order to function correctly and in fact one of the hormones created by the Thyroid gland is a complex structures derived from Iodine. This means correct diet is key to keeping the thyroid under control, but unfortunately in both cats and Humans correct Thyroid function can fail, leading to all sorts of issues.

Overactive Thyroid

An over-active Thyroid or 'hyperthyroidism' is a condition where too many hormones are produced. This leads to excessive weight loss even when constantly eating. There are possible treatments for over-active thyroid for cats, unfortunately these can have severe side effects including the promotion of heart issues and strokes. If properly monitored and administered, medication can prolong the life of your pet cat, however treatment isn't cheap - expect to pay several hundred pounds per year for medication and the same again for repeat vet visits.

Hyperthyroidism In Cats

Hyperthyroidism is a condition which has long been recognised in humans. However, cats were not diagnosed with the condition until the 1970s. Causing weight loss despite a voracious appetite, hyperthyroidism is now instantly recognisable as it has become so common in felines. Which makes you wonder what could have caused such an epidemic? Could it be that an aspect of our modern lifestyles has led to the prevalence of yet another health issue? One vet in America certainly suspected that this would prove to be the case when he first discovered that so many cats were experiencing thyroid related issues.

The First Case of Hyperthyroidism in Felines

In 1978, New York vet Dr Mark Peterson met Sasha, a cat suffering from severe weight loss with no apparent cause. His colleagues were scratching their heads in despair. Despite never having seen a cat with hyperthyroidism, Peterson wondered if this condition could be to blame and asked a doctor to scan the animal. The scan revealed a benign tumour on the cat's thyroid gland. One of his colleagues then informed Peterson of five further cats suffering from the same symptoms. These animals were all later found to have compromised thyroid glands.

Hyperthyroidism Across the World

It wasn't long before Dr Peterson had encountered over 100 cases of the condition. A condition which, until that time, cats had not suffered from. In 1979 Peterson delivered a presentation at a veterinary conference in Seattle in which he outlined five cases of hyperthyroidism in cats. This caused quite a stir and stories of hyperthyroidism in cats across the USA began to emerge. As the years went by more and more cats seemed to be suffering from the condition which was now appearing around the world.

Potential Causes

Treatments for hyperthyroidism were soon developed but it has taken a lot longer to find out why hyperthyroidism seemingly appeared from nowhere. A number of experts, including Dr Peterson, have spent many years researching possible causes all the time suspecting that dietary, environmental or lifestyle factors had to be to blame. Their efforts uncovered a long list of potential suspects but now a front runner has emerged.

Hazardous Chemicals

Polybrominated diphenyl ethers are chemicals which were used as fire retardants in many household items including carpets, underlays, sofas and electrical goods. These chemicals leached into household dust and then settled around homes. The chemicals also happened to possess chemical structures similar to thyroid hormones. These fire retardants were introduced in the 1970s! They have now been withdrawn but take years to degrade and so many households will still be polluted with them.

Born in the USA

The chemicals were first used and most heavily used in the USA which would explain why hyperthyroidism in cats appeared there first. Cats roll on the floor, sit on the sofa and lick themselves and so are likely to ingest any chemical residue which has settled. Researchers had also noted that indoor cats were the most to susceptible to hyperthyroidism and so the fire retardant theory also explains this anomaly.

Hopefully the incidence of hyperthyroidism will now begin to decline. Probably to be replaced by another nasty disease that human lifestyles have caused!

Other treatments for Hyperthyroidism include giving your cat radioactive Iodine, which lodges in the Thyroid gland and selectively kills off thyroid cells, bringing the condition under control. This treatment can of course have side effects including the promotion of cancerous growths. The presence of radioactive substances of course must be handled correctly so as not to affect any other animals or humans. Kitty litter becomes much more hazardous for all those who come into contact with it!


This condition is the opposite of an over-active thyroid and results in excessive weight gain and other issues related to the lack of thyroid hormones. Hypothyroidism can lead to very sluggish behaviour from your Cat, with excessive weight gain and problems throughout the body including brain, heart, bowels and kidneys.

Thyroid hormone replacement therapy can help your Cat to live a relatively normal life, but this has to be properly regulated and just like treatments for Hyperthyroidism can be expensive.

Living with a Hyperthyroid Cat

For those who have lived with cat which has Hyperthyroid condition, you will know that not only do expenses mount up but also your entire daily routine revolve around medication.

It can be pretty impossible to get your pet cat to swallow medication most of the time, so think creatively when getting your moggy to eat his tablets!

Meat and fish paste can work very well - roll up small balls of paste and put a tablet in each of these, you will probably find your cat will like these treats and swallow immediately, but experiment with the best delivery method and of course don't give your cat any more food until the medication has been given.

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