Comparison of Canine Thyroid Hormone Values Between Laboratories

Abstract
Blood was drawn from 10 dogs, serum harvested and frozen, and shipped to two laboratories, both of which measured total and free thyroxine (T4 and fT4), total and free triiodothyronine (T3 and fT3), thyroglobulin autoantibody (TgAA), and thyroid-stimulating hormone (TSH). Information was collected about the dogs including past thyroid hormone testing, thyroid supplementation and other medications, chronic disease conditions including allergic dermatitis, and diet. Values differed between laboratories in four of six dogs with complete data (67%). One laboratory recommended thyroxine supplementation for four of the dogs; the author of the study did not recommend thyroxine supplementation for any of the dogs based on thyroid hormone results and clinical presentation. [...]