Ferguson D.
Feline Health Topics for Vets, 1986. 1(2): p.1-6.
The specific cause(s) of feline hyperthyroidism is not known. Spontaneous remission, with out the use of some type of medical or surgical treatment, does not occur. Consequently, the aim of treatment for feline hyperthyroidism is to control the excessive or inappropriate secret ion of thyroid hormones from the  hyperfunctional thyroid glands ( i.e. thyroid adenomatous hyperplasia or adenoma). Interestingly, thyroid carcinoma as a cause of feline hyperthyroidism occurs in only 1-2% of the reported cases.