Thyroid scintigraphy illustrating scans of (A) clinically normal cat; (B) cat with goitrous hypothyroidism; and © cat with atrophic hypothyroidism.


Spontaneous primary hypothyroidism appears to be an extremely rare clinical disorder in adult cats, with only 4 reported cases over the last 25 years.

Most hypothyroid cats are younger (generally kittens, aged 2–4 months) and suffer from congenital hypothyroidism, which typically results in disproportionate dwarfism (cretinism).

Of approximately 60 cats with congenital hypothyroidism that have been reported, only 3 were older than 12 months of age at time of diagnosis, but these 3 cats were stunted since kittenhood, consistent with the diagnosis of congenital hypothyroidism.

In dogs and humans, almost all naturally occurring hypothyroidism is attributable to irreversible destruction of…

Dr. Peterson was involved in a recent study which linked the use of flame retardants, and other common household compounds, to hyperthyroidism in cats.

This study, published in Environmental Science & Technology, used silicone pet tags to monitor feline exposure to various chemicals and compounds found throughout the home. These silicone tags were attached to a standard cat collar (see photo above), and most owners reported that wearing the silicone tags didn’t bother their cat at all.

The concern, in general, is that cats are being exposed to OPEs inside the home. OPEs (organophosphate esters) are one type of flame…

Dr. Mark E. Peterson

Dr. Mark E. Peterson is a world-renowned veterinarian specializing in endocrinology (hormonal disorders).

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store