Effectiveness of blood electrolyte homeostasis regulation in polar foxes (Alopex lagopus, Linnaeus 1758)

The Arctic fox (Alopex lagopus, L. 1758) is maintained in captivity for breeding purposes due to the high quality of its winter fur. The success of breeding these animals depends primarily on their health, which determines high reproductive rates, low neonatal mortality and proper development of young animals. A prerequisite for maintaining good health is the maintenance of a constant internal environment, especially water-electrolyte and acid-base homeostasis. Sodium, potassium and chloride are the main electrolytes affecting volemia and osmolality of body fluids. In the current study, the results regarding the renal capacity of six-month-old foxes to regulate sodium, potassium, and chloride levels are presented, considering the sex of these animals. It has been shown that the concentration of sodium, potassium, and chloride in the blood serum of six-month-old polar foxes, as well as the osmotic pressure of the blood serum, were within the upper limits of physiological normal range. Higher concentrations of sodium and potassium were observed in males of these animals. Nonetheless, the results indicated efficient regulation of blood electrolyte homeostasis, both in females and males.