Main problem: At present, service, decorative and hunting dog breeding is intensively developing in Russia and in the Tula region. So, in 2020, 119 high-breed puppies were registered in the Book of Pedigree Breeding, and in 2021 already 164 puppies, mostly decorative and service breeds. Thus, the number of pedigreed dogs susceptible to various infectious diseases is increasing annually. Canine distemper is one of the most widespread viral diseases of dogs all over the world, including in Russia. Analyzing the "Patient Admission Logs" of veterinary clinics in the city of Tula, it was found that 44 % of dogs that fell ill with diseases of infectious etiology were diagnosed with canine distemper. Purpose: The aim of our research was to study the epizootological features of the course of canine distemper among dogs in the Tula region of Russia. To achieve the intended goal, it was necessary to solve the following problem: to analyze the breed and age factors for the incidence of canine distemper. Methods: Analysis of data from private veterinary clinics reporting on the incidence of small domestic animals was used. Results and their significance: As a result of studying the epizootic situation of canine distemper among dogs, the following data were obtained: The disease is observed throughout the year and has the character of undamped fluctuations subject to sharp seasonal changes. The maximum number of diseased dogs in all years of observation is recorded in March - 6.2 cases per 1000 individuals. It has been established that among the infectious diseases of dogs, distemper occupies the first place, and there is an annual increase in the number of dogs with distemper.