СОСТОЯНИЕ ЭПИЗООТОЛОГИЧЕСКОЙ СИТУАЦИИ ПО ИНФЕКЦИОННЫМ И ИНВАЗИОННЫМ БОЛЕЗНЯМ БЕЗНАДЗОРНЫХ СОБАК В УСЛОВИЯХ МЕГАПОЛИСА И РАЗРАБОТКА АЛГОРИТМА ЭПИЗОТОЛОГИЧЕСКОГО МОНИТОРИНГА

Stray dogs pose a serious threat to veterinary and public health due to their potential role in the transmission of infectious and parasitic diseases. The aim of this study was to investigate the epizootiological situation among stray dogs, determine the prevalence of infectious and parasitic diseases, and develop preventive measures in a metropolitan setting. The study was conducted from 2024 to 2026 in the city of Uralsk, West Kazakhstan Region. During the study period, a total of 4,422 stray dogs were registered. The animals were registered, underwent clinical examination, and were placed under quarantine observation; taking into account their clinical condition and habitat, biological samples were collected from them for laboratory testing. Diagnostics were performed using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). In 2025, the highest seropositivity rates were recorded for toxocariasis (88.8%), listeriosis (85.6%), pasteurellosis (85.0%), and brucellosis (75.0%). During molecular genetic analysis, Toxocara canis DNA was detected in 46.6% of the fecal samples tested, and Echinococcus DNA was detected in 29.3%. In 2025-2026, 170 of the 218 dogs examined (78.0%) tested positive in three or more serological tests, and 95 animals (43.6%) were found to be seropositive when tested simultaneously for 5-6 infectious and parasitic diseases. In 2026, seropositivity rates were as follows: toxocariasis-32.9%, echinococcosis-28.2%, leptospirosis-22.8%, tuberculosis-21.5%, pasteurellosis-20.8%, chlamydiosis-19.5%, and brucellosis-14.8%. In a PCR analysis conducted in 2026, DNA from the bacterial pathogens under investigation was not detected in 149 blood samples, whereas DNA from Toxocara canis was detected in 8 of 29 fecal samples (27.6%). The results indicate a significant infectious and parasitic burden among the stray dogs examined and underscore the need for systematic epizootiological surveillance combining clinical, serological, molecular genetic, and parasitological methods. Based on the study results, an algorithm for epizootiological monitoring was developed, which includes animal registration, clinical examination, quarantine, selective laboratory testing, epizootiological risk assessment, treatment, and, if necessary, isolation, vaccination, deworming, spaying/neutering, follow-up monitoring, and forecasting. The proposed approach makes it possible to create an epizootiological map of the spread of infectious and parasitic diseases among dogs in a metropolis, determine the level of risk, and identify potential sources of pathogen transmission.