Determination of the tolerability of the combined vaccine against Rhinopneumonia and Strangles on young horses

Infectious diseases are registered annually in herd horse breeding. One of the most common diseases among young horses are rhinopneumonia and strangles. According to the Department of Veterinary Medicine of the Republic of Sakha Yakutia and its own research, rhinopneumonia is registered annually in many districts of the republic, and the incidence of horse strangles is 57.8-62.7% annually, and the mortality from these diseases reaches up to 20%. One of the effective methods of combating these diseases is vaccination. In this regard, we have developed a new combined vaccine against rhinopneumonia and strangles for young horses. Preclinical studies on white mice have established harmlessness, absence of toxicity and pyrogenicity. The preclinic was completed by determining the tolerability on young horses (target animals) with single and multiple administration in preventive and increased doses. After immunization, the foals of all experimental groups in the blood, regardless of the multiplicity and number of doses of the vaccine, developed antibodies to the rhinopneumonia virus in titers 1:800 and 1:1600. The morphological composition of the blood of animals of all experimental groups exceeded the indicators of animals of the control group in terms of the content of erythrocytes and leukocytes. However, it should be noted that the indicators of the morphological composition of the blood of the control and experimental groups were within the physiological norm. Biochemical studies have shown that, in all groups (control, experimental), a decrease in total protein and its fractions was noted after vaccination. We attribute the decrease in these indicators to the influence of the method of keeping and feeding, since in the spring the young do not receive the necessary nutrients, vitamins and mineral elements. Thus, we have established the safety of a combined vaccine against rhinopneumonia and strangles for young horses in tested doses.