The results of the classification of infectious diseases of farm animals spread on the territory of the Republic of Sakha (Yakutia) for the period 2001-2021 are presented. It was found that there were 42 nosological units of animal diseases involved in the epizootic process on the territory of Yakutia. Infections in cattle are caused by 18 types of pathogens, horses - 12, reindeer - 4, pigs - 10, birds - 11, small ruminants - 3, fur-bearing animals - 7, other types of animals - 9. According to the OIE classification, 10 nosoforms of diseases are common in Yakutia: rabies, brucellosis, viral hemorrhagic septicemia, equine infectious anemia, avian infectious bronchitis, infectious bovine rhinotracheitis, paratuberculosis, pasteurellosis and tuberculosis. Diseases not on the OIE list, including Marek’s disease, swine dysentery, colibacillosis, parvoviral enteritis, salmonellosis, diamond-skin disease, blackleg were registered. A number of nosoforms common in Yakutia belong to particularly dangerous diseases for which restrictive measures (quarantine) may be imposed. These include actinomycosis, rabies, brucellosis, infectious equine anemia, avian infectious bronchitis, infectious bovine rhinotracheitis, bovine leukosis, leptospirosis, paratuberculosis, diamond-skin disease, tuberculosis and canine distemper virus. A number of diseases (Marek’s disease, carnivorous infectious hepatitis, bovine leukosis, horse strangles, avian ornithosis, egg drop syndrome, diamond-skin disease, and blackleg) are peculiar to only one species of animals. Many infections are characterized by the persistence of the pathogen in different species of farm and small domestic animals, birds and wildlife, which determines the interspecies degree of epizootic danger of these infections. Infections of bacterial etiology (bacterioses) prevail in Yakutia with 21 nosoforms. Viral diseases (viroses) are represented by 15 nosoforms, mycoplasmosis and chlamydia - one each. The most numerous infections are those with the main alimentary, or fecal-oral, route (22 diseases). Ten infections, including infectious atrophic rhinitis, infectious bovine rhinotracheitis, distemper, are classified as airborne or respiratory (major) pathogen transmission. Transmissive carry-over (by vectors) is characterized by actinomycosis and infectious equine anemia; through the outer covers (without the participation of vectors) - 5 diseases, including balanoposthitis and rabies. The majority of the infections are characterized by one or more additional mechanisms of transmission (rabies, Marek’s disease, bovine leukemia, diamond-skin disease, etc.) in addition to the main mechanism of transmission of the pathogen. According to the source of the causative agent for all diseases (ktenonoses) they are domestic animals, but for such infections as rabies, Marek’s disease, viral hemorrhagic septicemia, leptospirosis and others, along with domestic animals, wild animals are an additional source (ktenotherionoses). In terms of susceptibility, most infections (30) belong to zoonoses peculiar only to animals; the remaining 12 belong to the more dangerous zooanthroponoses common to animals and humans.
