Hypothyroidism in Cats

Just about everyone has heard of hypothyroidism, or underactive thyroid, in human beings, but few are aware that our feline friends can also suffer from thyroid trouble. Just like us, cats have a thyroid gland which produces the essential thyroid hormones that regulate the metabolism, the body temperature, and the heart rate. The good news is, first of all, that it is a fairly rare condition in cats, and secondly, that it is transitory (short-term) and it does not need intensive treatment of any kind. As contradictory as it sounds, hypothyroidism in cats often follows treatment for exactly the opposite condition – hyperthyroidism or overactive thyroid. The symptoms are fairly distinctive. Let’s take a look at them.

Lazy, fat cat? Get that thyroid checked

In combination, the symptoms of hypothyroidism in cats are quite distinctive, and most of them are easily recognizable if you know your cat’s habits. They include laziness, weight gain, hair loss – especially on the ears, matted hair and an ungroomed appearance. One symptom you might not notice as easily, especially if your cat is free to come and go as it likes, is constipation. The body temperature will also be low, but you’ll probably only find this out when you visit the vet because nobody is likely to take their cat’s temperature at home. Another symptom in very young cats is delayed eruption of the teeth, but most people probably wouldn’t notice that either. If you notice these symptoms, your vet will take the cat’s temperature and have blood tests done to determine the levels of the thyroid hormones. It’s possible, though, that if your cat has another illness, the T4 hormone levels measured will be low due to the illness, so more extensive testing is required to be sure. As already mentioned, hypothyroidism is usually transitory, so oral treatment will only be administered if the symptoms are serious. In this case, it usually clears up after just a few weeks of treatment – a few months at the most. If your cat has been diagnosed with hypothyroidism, do not be too alarmed. The prognosis for your furry friend is very good, and the condition is usually quite short-lived, and puss will soon be her active, quirky self again. Whether you get veterinary help – which is advisable – or not, you can boost your cat’s thyroid activity with certain foods or supplements.

Supplements for cats with an underactive thyroid

  • Kelp – this well-known sea alga is an excellent thyroid function booster in both animals and humans. Because it grows in the ocean, it is full of iodine, which is arguably the most important mineral for thyroid activity. If you buy it in powder form or crush the tablets, you can mix it into her food, and Puss won’t even know she’s taking her medicine!
  • Astragalus root – never heard of it, right? Astragalus is a very pretty plant from the legume family. It is also known as vetch, goat’s thorn or locoweed. It boosts the entire endocrine (hormone production) system and regulates the thyroid hormones. It is also available in powder form, so it’ easy to administer.
  • Lactobacillus probiotics – probiotics help by boosting the immune system, which can be helpful, even if your cat isn’t suffering from hypothyroidism. These are best administered in capsule form because the capsules resist the stomach acid and only dissolve in the gut, where the bacteria are released to do their work.
  • Calcium – this is an essential element for all forms of life, and your feline is no exception. Calcium powders mixed into the food are the easiest to administer.

And a few “don’ts” – never give your cat sugar in any form. I know this sounds strange, and cats, being cats, usually aren’t interested in anything sweet, but old habits die hard and young cats, just like young people, are easy to influence, and unfortunately, some people give their cats chocolates and candy! And those other empty carbs are also a bad idea – think of the big, red pizza-eating cartoon cat!


So, off to the supermarket or the pet store and stock up on those healthy additions to your feline’s diet. You might only be able to get some of them online, but now you know what you need to do! Just like in humans, you need to be consistent and persistent with the treatment. Giving tablets to a cat isn’t all that easy, but it isn’t impossible either. Prepare everything well in advance, then wait for her to forget about it – she’ll hear you opening the container with the tablets and disappear in a flash if she can, so close the doors and windows before you do so. Then wait until she is sleeping peacefully somewhere, pick her up and wrap her tightly in a towel – especially those forelegs – then put her under your arm with those strong hindlegs pointing harmlessly backwards, squeeze her jaw with thumb and forefinger, right at the back, so that she is forced to open her mouth, then push the tablet right virtually into her throat and hold her until she has swallowed it. If you’re afraid she’ll bite you, wear a pair of thick gloves. But it’ll be all over in a jiffy – she’ll hate you for an hour or two, but she’s a cat, after all!