Cat Owners

Help Prevent It


The prevention of hyperthyroidism in cats is not straightforward. However, research suggests that several factors may, over time, combine to cause the condition.

The cause of feline hyperthyroidism is not fully understood, which makes prevention more problematic. Although unproven at this point, certain factors have been associated with feline hyperthyroidism, so it may be worth trying to regulate your cat’s contact with these factors in the hope of decreasing their vulnerability to the disease.

These factors include:

  • In your cat’s diet: iodine levels, soy protein (found in many commercial cat foods), and various trace elements;
  • The material of the container in which your cat’s food is packaged;
  • Fire retardants in the home;
  • Herbicides (weedkillers);
  • Pesticides, including products which kill cat fleas – both as spot-on treatments and for treating the home; and
  • Cat litter.

To do your best to prevent hyperthyroidism in your cat, our guidance would be:


  • Avoid soy protein, fish, and giblet flavours;
  • Use pouches rather than cans for moist food;
  • If you must use cans, choose smaller (eg 85g) cans;
  • Aim for the recommended iodine concentration (0.5-2ppm);
  • Ensure the right amount of vitamins and minerals;
  • Consider home cooking to avoid potential contaminants (but ask a veterinary nutritionist first); and
  • Use ceramic or metal dishes, avoiding cling-film and plastic containers.

Drinking Water

  • Consider using a good tap-water filter; and
  • Avoid bottled or demineralised water.

Cat Litter

  • Choose natural biodegradable cat litter, without deodorisers or other chemicals.


  • Avoid fire retardants becoming accessible to cats, such as when foam packing or mattresses become aged and the covering is damaged; and
  • Try to avoid products with bromine-based fire retardants.


  • Consider wiping your cat’s coat daily with a damp cloth;
  • Consider bathing your cat monthly;
  • Minimise house dust and consider using a HEPA air filter in your home; and
  • Use topical and environmental flea treatments sparingly.


Even if you were to follow all of these recommendations, there’s no guarantee that your cat won’t develop hyperthyroidism. However, following them shouldn’t harm your cat, and they are only intended as a guide to offer you some awareness. It’s important to discuss your own cat and his or her individual circumstances and dietary needs with your vet, first.

Our advice is based on the recommendations of Dr Mark Peterson,  an international expert in the field of feline hyperthyroidism.