[Seasonal effect on serum levels of thyroid hormones in German shepherds and dachshunds and their health status].

A relatively frequent prevalence of dermatoses in summer has drawn our attention. Dermatoses of endocrine origin occur very often. We have noticed the deterioration of skin changes in animals with hypothyroidism. Bubeník et al. (1983), Webster et al. (1991), Reiter et al. (1988) reported that changes in concentrations of thyroid hormones were found in fallow-deer, sheep and hamsters due to the effect of temperature and season. Based upon this knowledge we have decided to observe the health status and function of the thyroid gland in two randomly selected groups of various size dogs--German shepherd and dachshund during four seasons. We observed following parameters: concentration of triiodothyronine (T3), thyroxine (T4), cholesterol (Chol) and total lipids (TL) in the blood serum, average temperatures in individual seasons. Blood was always withdrawn fasting in the morning from vena antebrachii. Concentrations of T3 and T4 were determined by the commercial kits RIA-test-T4 and RIA-test-T3 (Human-Lab, Kosice, Slovak Republic). The levels of cholesterol and total lipids were determined by the BIO-LA-tests (Lachema, Brno, Czech Republic). March, April, May were included into spring season; June, July, August into summer; September, October, November into autumn; and December, January, February into winter. The Slovak Hydrometeorologic Institute in Kosice provided the values of average temperatures in observed seasons. The average temperatures in individual seasons were the following: spring +9.8 degrees C, summer +18.4 degrees C, autumn +8.5 degrees C, winter -1.2 degrees C. During the observed period concentrations of cholesterol and total lipids ranged within the reference values in both breeds.(ABSTRACT TRUNCATED AT 250 WORDS)