"The importance of service dog breeding for humanity is difficult to overestimate. Infectious and invasive diseases are a limiting factor for breeding and improving dog breeds. They not only bring ignificant economic damage, do not allow the use of dogs in various sectors of the economy, sports, the army, law enforcement agencies, exchange of animals, and can also be dangerous to people. Such diseases include dirofilariasis-the only helminthiasis, which in the temperate continental climate of our country is transmitted by transmission through mosquitoes. The work-studies some issues related to the epizootology of dirofilariasis in domestic and wild canines and the distribution of D. immitis in domestic dog and common jackal. It also specifies the range of the intermediate hosts of this nematode. In the natural and urbanized territories of Uzbekistan four species of mosquitoes from the genera Anopheles, Aedes and Culex were identified as the nematode’s intermediate hosts; the rate of their infection with D. immitis larvae was 2.4–5.6%."