TSH concentration as a diagnostic test for feline hyperthyroidism

The finding of a high serum total thyroxine (T4) concentration allows a straightforward diagnosis of hyperthyroidism in older cats presented with classical clinical features of the disease. Cats with suspected hyperthyroidism routinely are screened by measuring T4, because it is inexpensive and specific. However, in many cats, particularly in the early phase of hyperthyroidism, T4 concentrations remain within the reference interval. Concurrent nonthyroidal illness can also suppress high serum T4 concentrations to within the reference interval.
Source: Advances in Small Animal Medicine and Surgery - Category: Veterinary Research Tags: Clinical Pathology Source Type: research