Abstract
Since first reported in the late 1970s, there has been a steady but dramatic increase in theworldwide prevalence of hyperthyroidism in cats. It is now regarded as the most commonfeline endocrine disorder, with diabetes mellitus coming a close second. Not only is thereevidence for an increased worldwide prevalence of feline hyperthyroidism, but also forgeographical variation in the prevalence of the disease. Despite its frequency, the underlyingcause(s) of this common disease is or are not known, and therefore prevention of thedisease is not possible. Due to the multiple risk factors that have been described for felinehyperthyroidism, however, it is likely that more than one factor is involved in its pathogenesis.Continuous, lifelong exposure to environmental thyroid-disruptor chemicals or goitrogens infood or water, acting together or in an additive fashion, may lead to euthyroid goitre andultimately to autonomous adenomatous hyperplasia, thyroid adenoma and hyperthyroidism.This review aims to summarise the available published evidence for the changes observedin the worldwide prevalence of the disease, as well as risk factors that may contribute todevelopment of hyperthyroidism in susceptible cats.
Highlights
IntroductionFeline hyperthyroidism (thyrotoxicosis) is a multisystemic disorder arising from excess production of the active thyroid hormones (tri-iodothyronine [T3] and/or thyroxine [T4]) from an abnormally functioning thyroid gland (Mooney 2010)
Feline hyperthyroidism is a multisystemic disorder arising from excess production of the active thyroid hormones from an abnormally functioning thyroid gland (Mooney 2010)
The substantial flaw in the logic of ‘pointing the finger’ at any one of these is how they could cause the disease to develop in cats on different continents within a relatively short period of time
Summary
Feline hyperthyroidism (thyrotoxicosis) is a multisystemic disorder arising from excess production of the active thyroid hormones (tri-iodothyronine [T3] and/or thyroxine [T4]) from an abnormally functioning thyroid gland (Mooney 2010). 97% – 99% of cases result from benign nodular hyperplasia, adenomatous hyperplasia or adenoma of the thyroid gland (Gunn-Moore 2005). 1% – 3% of cases are caused by mild to moderately malignant thyroid carcinoma (Gunn-Moore 2005). The disease has been reported in cats of between 8 months and 22 years of age, with a mean age of 13 years (Gordan et al 2003; Peterson, Randolf & Mooney 1994). 5% of hyperthyroid cats are younger than 10 years at time of diagnosis (Peterson et al 1994)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call