COMPARATIVE EXTENSITY AND INTENSITY OF ESTROSIS IN SHEEP DEPENDING ON ANTIPARASITIC TREATMENTS

Abstract

The period from the beginning of spring to the end of October is the most dangerous period for sheep. It is at this time that sheep gadflies (Oestrus ovis) are activated, which lay larvae in the nasal cavity of animals. In the future, parasites attack the nasal mucosa, frontal, horny and maxillary sinuses. In the body of a sheep, more than 100 larvae can remain from the vital activity of just one female gadfly, which bother the animal throughout the year. Infection with larvae of sheep gadfly is called «estrosis of sheep». It is dangerously high risk of infection, inflammation of the nasal cavity and even the lining of the brain, which leads to a decrease in productivity and the death of livestock. The latest reports on the spread of sheep gadfly and seasonal dynamics of the level of gadfly infestation in sheep in the southern region of Russia by the beginning of our research were more than a decade ago. The objective of our research was to study the extent and intensity of the invasion of sheep estrosis in the arid zone of the Stavropol Territory, in connection with climatic changes and the ongoing spring chemotherapy with ivermectin drugs against helminthiasis in young sheep. We have been monitoring the clinical manifestations of sheep estrosis over the past three years in sheep farms of the steppe zone of Apanasenkovsky and Ipatovsky districts of the Stavropol Territory. In recent years, the duration of the summer of the imago gadfly has been extended to 8 months due to an earlier stable increase in temperature above +15 oC. Already at the end of March at the beginning of April and the end of the mass summer of the imago gadfly until the end of October, as a result of which two generations of the band gadfly are developing.