Factors influencing the intensity of Thelazia sp. infection in cattle in the Labinsk district of the Krasnodar territory

The purpose of the research is to determine factors affecting the spread rate of thelaziosis in beef breeds grown in the environment of the Labinsk district, the Krasnodar Territory, at the premises of Agrofrma Progress, LLC.Materials and methods. To determine factors that affect the spread of thelaziosis, a clinical examination of the Aberdeen Angus cattle of different sex and age groups was performed in Agrofrma Progress LLC. Swabs were taken from the conjunctiva of animals with clinical signs of thelaziosis for further microscopic examination. In 2020, 236 cattle were examined including 42 adult animals older than two years, 77 animals at the age of one year and 117 calves from 0 to 6 months. The species of the pathogens was identifed in the study of the conjunctival swabs according to the adult Thelazia morphology (Gorodovich N. M., 1967). To control ectoparasites and prevent thelaziosis, an insectoacaricide from the synthetic pyrethroid group was used. The study was performed on two livestock farms of Agrofrma Progress, LLC located on different terrains: in a temperate steppe zone with a dry climate and artifcial pastures and in a mountainous zone with a humid climate and natural pastures.Results and discussion. For 2019–2020, thelaziosis was recorded in 236 Aberdeen Angus cattle in the Progress agricultural frm of the Labinsk District, the Krasnodar Territory. A pronounced seasonal dynamic was determined; the spread of infection was recorded from the end of May to October; and the infection peak was in August. We observed a clear correlation of the infection with the activity of zoophilic flies, carriers of thelaziosis. The most widespread thelaziosis was observed in young cattle aged up to 6 months, that were kept on livestock sites on flat terrain in a drier climate.