Factors influencing serum concentrations of total thyroxine, free thyroxine and thyrotropin in healthy dogs of various breeds

摘要

The aim of this article is to obtain the correct specification of reference ranges of TT4, fT4 and cTSH with regard to the influence of physioJogical factors on thyroid gland functioning, including breed size, age and season. The reference range for TT4 was divided according to the size of the dog breeds. In large breeds, over 27 kg of live weight, it should be represented by the interval TT4 = 17-43 nmol/l; in medium size breeds, from 12 to 27 kg of live weight, it should be TT4 = 23-50 nmol/l and in small breeds, up to 12 kg of live weight, the reference range should move within TT4 = 27-55 nmol/l. The reference range of free thyroxin does not depend on the size of the breed and it is represented by a uniform standard: fT4 = 10-22 pmol/1. The reference level for cTSH in healthy dogs should not exceed cTSH = 0-0.35 ng/ml.