EN
The aim of the studies was to evaluate the usefulness of determining the level of haptoglobin, IgG and lysozyme in sera for monitoring the state of health of breeding polar foxes of different behavior at the preparturient period. It was found that in determining the physiological parameters of unspecific humoral immunity, the behavior of the animals should be borne in mind. Significant differences exist in the examined parameters of unspecific immune responses and behavior of foxes. The highest and statistically significant level of haptoglobin, IgG and lysozyme was noted in fearful foxes in comparison to aggressive and confident animals. It can be assumed that lower phagocytic and bactericidal activity noted in the fearful foxes in comparison to that in the aggressive and confident animals is compensated by a higher bacteriolytic activity of lysozyme and a higher level of serum IgG.