Broussard J.D., Peterson M.E. and Fox P.R.
Hyperthyroidism is the most frequently diagnosed endocnnopathy in cats. The number of cats determined to have hyperthyroidism has increased markedly over the past 10 years, since the first clinical cases of hyperthyroidism in cats were reported in l979 and 1980. In the early 1980s, clinical studies of hyperthyroidism in cats were performed at several veterinary institutions. In these studies, from which much of the current literature is based, cats were found to be severely affected by the disease, with typical clinical signs of weight loss, polyphagia, and hyperactivity approaching a prevalence of 75 to 100%. Today, screening of cats for hyperthyroidism by laboratory testing is more prevalent, and many cats with hyperthyroidism appear to have less severe clinical signs than those cats in which the disease was diagnosed 10 years ago.