Primary Hypothyroidism and Thyroid Goiter in an Adult Cat

Galgano M., Spalla I., Callegari C., et al.


Journal of Veterinary Internal Medicine, 2014. 28(2): p.682-686.

A 5-year-old, neutered male domestic shorthair cat was referred for evaluation of suspected hypothyroidism. In the previous 2 months, the owner reported mild lethargy, weight gain with decreased appetite, unkempt hair coat, and an episode of bilateral exter- nal otitis that temporarily improved after a 10-day treatment with ear medications containing gentami- cin, betamethasone, and clotrimazolea; treatment was completed 50 days before presentation. The cat had been slightly overweight for several months before the referring veterinarian was consulted, but more precise information was not available from the owner. The cat was started on a commercial diet to control obesity.b One month before admission, the referring veterinarian performed a CBC, serum biochemical profile, and urinalysis, and the results were unremarkable. In addi- tion, serum total thyroxine concentration (TT4) was within normal limits (1.1 lg/dL; reference range, 0.8– 4.7) and free thyroxine concentration (fT4), measured by chemiluminescence immunoassay (CLIA), was low (<3.9 lg/dL; reference range, 9.0–33.5).