The aim of this study was to investigate the immunological resistance of rabbits of 6, 5-7 months of age. The research was carried out on the basis of the private farm "Kuts" in 2016-2017,three groups of animals, 10 heads in each group, were formed. The control group consisted of clinically healthy animals, the experimental group 1 included animals  with mild loca ldamag e on one pinna in the form of (red tubercles, then bubbles, from which flew light yellow liquid, it dried up and formed scabs of grey-brown color, they turned into dense crusts with suppuration). In the experimental group 2 there were the animals with the invasion of two ears and the development of the entensive in flammatory process on them, the accumulation of a large number of crust sin the ear canal, the animals scratched the irears with the claw sof their limbs. The rabbits of White Giant, Californian and NewZealand breeds were used in the experiment. The hygienic, morphological, biochemical, immunological, zootechnical, biometrical methods were used in the research. The use of methods to detectpsoroptosis invasion and its effecton the immunological reactivity and theintensity of rabbitgrowth have been studied.The tasks of the experiment were:

- to study hygienic conditions of maintenance on the manifestation of psoroptosis invasionin the conditions of closedpremises;

- to determine the changes of morphological and biochemical parameters in the rabbits having psoroptosis with different forms oft he course of the disease;

- to determine the immune state of the rabbits having psoroptosis by the conten to fimmunoglobulins and thenumber of T and B lymphocytes;

- to determine thegrowth rate and the intensity of the average daily weight gains in the sick rabbit sand clinically healthy ones.

The tasks were solved with the use of the methods of natural resistance–bactericidal activity of blood serum (BASK) was determined by the nepholemetric method ccording to O.V. Smirnova and TA. Kuzmina, 1966, the lysozymic activity of the blood serum (LASK) was determined by V. G. Dorofeychuk, 1968, the contentofthet ot alp rotein and its fractions were determined by V.E. Chumachenko, 1991, thenumber of T lymphocytes–according to Jondal M., 1972, the content of B-lymphocytes–according to Mendes N., 1973, the amount of serum immunoglobulins of the classesJgG, JgM, Jg A–according to Manchinietal., 1965. The cellular indices of the natural resistance (phagocyticactivity of neutrophils-FAN and phagocytic index – FI) weredetermined by S.I. Plyashchenko’ method,1979. The sanitary and hygienic conditions were monitored byt hemethods adopte din hygiene. Psoroptosi si saninvasive diseaseofr abbits, it often occurs in winter and in early springwhen the rabbits are kept in the closed premises, that is associated withhigh humidity,improper hygienic condition so fmaintenance and care, the crowding that cause sinten sivereproduction of psoroptuscunculi and their rapid spread. The rabbits with psoroptosis arel aging behind in growth, their immunological reactivity decreases, that is characterized by the following changes:

- the conten toftotal protein in the serum at a low physiological level – 56.71 ± 5.1, 59.9 ± 3.8 g / l,

- the decrease in the content of albumins in the blood serum by 16.1% (p≤0.05) and gamma-globulins by11.3% (p≤0.05), and the increase in the content of beta-globulins to the value of 21.68 ± 1.14 and 23, 52 ± 0.92%, especially in the rabbits with a severe form of psoroptosis;

-the suppression of the humoral link of immunity–bactericidal and lysozymic activity of blood serum and the decrease in the number of T and B lymphocytes;

- the decrease in the concentration of hemoglobin by 13-18.5% and the decreaseinthenumberoferythrocytes by 12.4 and 20.1% (p≤0.05);

- the depression oft he bodyweight and growth ntensity by 22.3% and 35.3% (p≤0.05).

Key words: hygienic factor, rabbits, resistance, immunoglobulins, T – and B – lymphocytes, psoroptosis.