Qualification work experiments were conducted from 2020 to 2024 at the department of physiology, pathophysiology and biochemistry of Odesa State Agrarian University. Purebred and domestic dogs were involved in the experiments. Blood of these dogs was collected in different phases of the sexual cycle and in the anestral period. It was made to determine indicators of the functional state of the endocrine and immune systems. Also, statistical data analysis of clinical examination of dogs in veterinary clinics of Odesa was carried out to study the peculiarities of the distribution of sexual cycle dysfunctions in dogs due to various external and internal factors. Immunohistochemical and morphological indicators of uterine tissue were studied after ovariohysterectomy using monoclonal antibodies to the main CD receptors of local immunity and progesterone.
The conducted researches provided an opportunity to obtain new scientific data on the influence of age, size, housing conditions and season of the year on the prevalence of dysfunctions of reproductive organs in bitches. The dependence of the distribution of dysfunctions depending on age has been established.
The results of the phagocytic activity of neutrophils (FAN), the absolute leukocyte count (ALC), neutrophils, lymphocytes and monocytes study during the sexual cycle showed that the ability of neutrophils to phagocytosis changed during the estrous cycle by 13% (р<0.05) on the 5th day, compared to the first day. During sexual cycle, the dynamics of the ALC tended to decrease on 21%. However, the populations of different cells had different regularities. Thus, on the background of the general trend of ALC decreasing, on the 5th day the content of neutrophils tended to increase, and lymphocytes - to decrease. A slight decrease in the monocyte population was also found. On the 10th day of estrus, all the populations of the studied cells had a tendency to decrease, and on the 15th day, the number of lymphocytes increased by 13%, and the tendency of the decrease in neutrophils remained. Unlike T and B lymphocytes, natural killer cells, which reflect innate cellular immunity, tended to decrease in dynamics during the follicular phases of the sexual cycle (first 10 days).
Studies of the cellular link of immunity in bitches during the sexual cycle, depending on age and season of the year, proved that the phagocytic activity of neutrophils during the cycle in young dogs had a tendency to decrease, from 3.38±0.84 G/l on the 1st day of the cycle – to 2.11±0.56 G/l on the 20th day. In animals aged from 2 to 6 years, from the 1st to the 5th day, this indicator had a tendency to increase, and during further analysis, it decreased. In bitches’ blood from 2 to 6 years old, from the 10th to the 15th day of the sexual cycle, a tendency to increase the absolute number of T-lymphocytes was observed. Later (up to the 25th day), there was a tendency to decrease. More pronounced changes in the number of lymphocytes on the 25th day were related to T-helper cells and NK lymphocytes. Reliable difference between groups on the 25th day was 27% (p<0.001) for T-helpers and 29% (p<0.001) –for NK lymphocytes.
New data were obtained regarding the cellular link of immunity in bitches with different states of the reproductive system. Thus, comparing the absolute number of leukocytes, it was established that in anestrus this indicator was 5.86±0.89 G/l in comparison with 5.43±1.53 G/l in the period of sexual desire and 5.68±0.08 G/ l – in conditions of pyometra. The indicator of the absolute number of lymphocytes was reliably (p<0.05) lower in the group of bitches with pyometra and was 1.48±0.35 G/l, which is 0.92 G/l less compared to the group of animals in the anestrous period. Analysis of the dynamics of progesterone content during the sexual cycle in bitches showed that on the 1st day of the cycle, its concentration was on average 2.13±0.11 nmol/L, which is characteristic of anestrus. During the next five days, a slight increase in progesterone content was noted (up to 3.27±0.69 nmol/L). On the 10th day of estrus, the hormone content increased reliably (P≤0.05) up to 6.48±0.54 nmol/L. This concentration is typical for the initial stage of the luteal phase of estrus. Determination of progesterone concentration in blood serum on the 15th day of estrus showed a significant (16-fold) reliable (P≤0.05) increase compared to the 10th day.
A method of predicting the development of dysfunctions of reproductive organs in bitches depending on the degree of body stress is proposed. It includes determining the percentage of inversion of T-"active" lymphocytes during addition (in vitro) of adrenaline. To reduce the risk of inflammatory processes in the uterus after the sexual cycle, it is necessary to determine the indicators of the cellular link of immunity and the phagocytic activity of neutrophils.
