DYNAMICS OF INDICATORS OF CELLULAR IMMUNITY IN PUPPIES DEPENDING ON THE MULTIPLICITY OF INTRODUCTION THE BIOLOGICAL STIMULUS
Authors: Broshkov M. M. , Fedkalova T. M. , Vishchur O. I. 
Published: May 2023

Study of immune-physiological indicators in puppies in critical periods of life, including and for the introduction of a biological stimulus, is an actual direction of modern researches. Actuality is related to a change in immunogenic properties of biological stimulus, a decrease in resistance of animal body, and lack of available methods for assessing the immune status of puppies after vaccination.

The purpose of the research was to determine the dynamics of indicators of the cellular link of immunity in puppies depending on the frequency of a biological stimulus (BS) introduction.

The experiment was conducted on 10 puppies from one brood. Puppies were divided into two groups: I – single vaccination at 51 days of life was done; II - two-time vaccination on the 28th and 51st days of life was done. Biocan DHPPi vaccine (Czech Republic) was used as a biological stimulus.

For conduction the immunological studies, blood from puppies’ the jugular vein at 7, 14, 28, 51, 71, and 90 days of age was used. On days 28 and 51 of the study, blood was taken directly 5 minutes before biological stimulus administration.

The absolute number of leukocytes, neutrophils, monocytes, lymphocytes and the phagocytic activity of neutrophils were determined in blood stabilized with heparin.

During the first month of the postnatal period, the absolute number of neutrophils in the blood of puppies of both groups was almost the same, the difference between the groups was within 0.2–0.7 G/l. Starting from the 28th day, a significant increase in the number of neutrophils in the blood of puppies was recorded, similar to when determining the number of leukocytes.

The analysis of the research results showed that the absolute number of lymphocytes, unlike other cells, had a clear tendency to decrease, starting from 14 to 70 days of age.

Authors' research established that regardless of the frequency of biological stimulus introduction, a physiological crossover occurs in the body of puppies. However, it should be noted that the biological stimulus affects the quantitative composition of lymphocytes and neutrophils. This is expressed in the fact that in the group of puppies, where the biological stimulus was administered, the increase in the number of neutrophils was 2 times less than in the other group (where it was not administered on the 28th day). Regardless of frequency of the biological stimulus introduction on 70 days, the number of neutrophil granulocytes and lymphocytes in the blood of both groups did not differ significantly and maintained this trend during the next three weeks of observation.

It was established that the administration of BS to puppies causes an immunosuppressive effect on the body, as evidenced by a decrease in the absolute number of neutrophils and lymphocytes in the blood. At the same time, administration of BS does not affect the phagocytic activity of blood neutrophil granulocytes.

Physiological crossover, namely a decrease in the absolute number of lymphocytes and an increase in neutrophils in the blood of puppies occurs after 28 days of life without connection to administration of BS. Further research is needed to study the feasibility of a two-time administration of the vaccine as a biological stimulus in the studied terms.