In the farms of the Udmurt Republic, the most common endoparasites of cattle are Fasciola hepatica, Chabertia ovina and Haemonchus contortus and their association. Feces samples were taken individually and examined by flotation and sequential swabs. The therapeutic efficacy of anthelmintic drugs has been studied in 780 cows. Animals’ infection rate was determined by triple helminthocoproovoscopic examination of fecal samples by flotation and sequential washing before and after antiparasitic treatments (15, 30 and 90 days after deworming). The high degree of cattle infection in various regions of the Udmurt Republic with fasciolosis and strongilatosis of the gastrointestinal tract is due to optimal climatic conditions for the regular transmission of the pathogen to susceptible animals. The therapeutic efficacy of anthelmintic drugs has been studied in 675 cows, which were divided according to the principle of analogues into groups consisting of 45 animals. According to the results of our studies in case of nematode monoinvasion, the most effective antiparasitic drugs are closanthin 20 % (the cost of one dose per animal is 77 rubles) and ivermectins (the cost of deworming per animal does not exceed 40 rubles). Analyzing the extenseffectivity of the studied anthelmintic drugs, we found that closantin 20 % at a dose of 1 is the optimal drug in terms of efficacy and cost for monoinvasions (ID – 100 %) with fasciola or strongilates of the gastrointestinal tract, and their association (ID – 93.3 %), 1.25ml / 50kg of animal weight.

The purpose of the research was to determine and comparatively analyze the degree of distribution of eimeria species in the northern, central and southern zones of Udmurtia and to identify various associations of these protozoa in farms. The studies of animals of black-motley, Holstein and holsteined black-motley breeds of animals aged 1–16 months, as well as heifers and cows in three zones of the Udmurt Republic showed that eimeriosis is recorded in all experimental farms regardless of the technology of keeping and breed of animals. In order to determine the species of eimeria, the method of oocysts culturing in a thermostat at 25–28 ∘C in a 2% solution of potassium dichromate was used [5]. The results of our studies showed that eight species of bovine eimeria are recorded in animals from the farms of the Udmurt Republic. In the farm located in the central region, the maximum prevalence rate was noted and the clinical signs of eimeriosis are most manifested, up to the death. In our opinion, this is due both to the high prevalence rates, a high percentage of infestation with the most pathogenic species, such as E.zuernii and E. bovis, and mixed infections, the most common of which are the following: E.zuernii + E.bovis; E.zuernii + E.bovis + E.ellipsoidalis; E.zuernii + E.bovis + E.bukidnonensis; E.zuernii + E.bovis+E.subspherica; E.zuernii + E.bovis + E.ellipsoidalis + E.auburnensis; E.zuernii + E.bovis + E.ellipsoidalis + E.auburnensis + E.bukidnonensis + E.subspherica + E.brasiliensis + E.alabamensis.

The infestation was studied and the structure of the parasite cenosis of ruminants of the Udmurt Republic was characterized. Over the period of several years of research (2016-2020), a diverse parasitophauna was identified. According to the results of the research, it was established that cattle is mainly invaded by Eimeria spp., nematodes of the Strongylata suborder, dicroceliosis dominates from trematode infestations. The maximum infection rate was noted by eimeriosis invasion, during the entire time of the studies it varied from 87.84 % to 77.73 %, which indicates a tendency to increase invasion and stationary problems of farms. The features of competitive relationships are clearly traced in hepatic flukes: dicrocoeliums and fascioles. Dicrocoeliotic invasion prevails on average by 32 %, which indicates a partial manifestation of antagonism.When analyzing the generic structure of the parasite complex of cattle, on average for five years, it was found that the largest share is occupied by Eimeria spp - 44.35, Strongylata - 30.52, Dicrocoelium - 17.52, Fasciola - 6.43, Eurythrema – 0.67 and Trichostrongylus – 0.51 are less represented. A retrospective epizootic analysis of parasitoses showed that sheeps, like cattle, have a diverse parasitophauna, but in the first case, the detection of monoinvasions is 3.5 times higher. In the structure of sheep parasite cenosis, similar indicators of infection with Eimeria spp, Strongyloides, Moniezia were found, generic indices ranged from 24.18 to 27.61. Strongylatosis of the gastrointestinal tract are replaced by Strongyloides. A significant change was also observed in the group of trematode infestations. Unlike cattle, fasciolosis prevails in sheep with a maximum value of 9.5 times in 2019, while dicroceliosis was not registered at all in 2017. In the sheep parasite complex, moniesiosis occupies the main share – 27.61, which may be related to the conditions of keeping, since sheeps are grazing for a long time and a meeting with intermediate hosts - oribatid mites is inevitable.

Metabolic disorders and dysfunctional state of the digestive organs lead to the development of distal extremities diseases. The greatest danger is neсrobacrillosis. Vaccination is one of the ways to prevent and control this disease. The article reflects the data on the effect of vaccination (“Nekovak” and formol-emulsion neсrobacrillosis vaccine of Federal Centre for toxicology, radiation and biological safety) on immunological and serological parameters of blood and blood serum of cattle in the Udmurt Republic. After immunization with “Nekovak” vaccine and formol-emulsion neсrobacrillosis vaccine, we determined an increase of the number of leukocytes to 7th day, and also an increase of T-lymphocytes to 14th day. The number of B-lymphocytes reaches a maximum on 21st day. The content of gamma globulins, including specific antibodies against the neсrobacrillosis pathogen, exceeded the control and reached a maximum on the 21st day after vaccination.