Physiological changes, in German shepherd, in metabolic and endocrine parameters most frequently used in the diagnosis of canine hypothyroidism

Abstract

The aim of this study was to investigate if plasma concentrations of thyroid hormones and metabolites used in the diagnosis of hypothyroidism, hormones were affected by gender and age. For this purpose 57 German shepherd clinically healthy canines were used. They were grouped by sex (32 males and 25 females) and age category (young, 0-4 years and adults, 5-12 years). The determination of cholesterol, triglycerides, high density lipoproteins, and low density lipoproteins in serum was measured by spectrophotometry. Hormones were measured by radioimmunoassay (T4T) and immunoradiometric assay (TSH). The concentrations of T4T and TSH were affected by gender (females had higher TSH and lower T4T concentrations, P=0.036 proteíand P=0.003, respectively) and age (young dogs showed higher TSH and lower TT4 levels, P=0.002 and P=0.006). The cholesterol and triglyceride levels were affected by the gender, females presented higher concentrations (P=0.006 and P=0.003, respectively). The lipid fractions were changer with age: young animals had lower levels of cholesterol and LDL (P=0.062 and P=0.023), but high levels of HDL (P=0.051). No age effect on triglyceride levels was detected. We conclude that in healthy German shepherd breed dogs, there are endocrine - metabolic parameters used in the diagnosis of hypothyroidism that are affected by gender and age.