Morphological features of the causative agent of chorioptic mange isolated from cattle

Abstract

Providing veterinary care against parasitic diseases is one of the factors that affect the possibility of effective and profitable introduction of the livestock sector. Chorioptic mange is one of the globally spread invasive diseases of cattle caused by persistent ectoparasites. The diagnosis of chorioptosis is based on the microscopic detection of mites in scrapings from the skin of the affected animal with mandatory identification of the parasites. The aim of the research was to investigate the morphological features and metric parameters of Chorioptes mites isolated from cattle. Mites isolated from cattle were morphometrically identified as Chorioptes texanus. Morphological features of male Ch. texanus mites include peculiarities in the structure of the opisthosomal lobes and of the setae located on the opisthosomal lobes, opisthosoma and tarsus of leg III. 14 morphometric parameters characterizing the general structure of the body (length, width and their ratio, length and width of the gnathosoma, length of the idiosoma, proterosoma, podosoma, propodosoma, metapodosoma, hysterosoma, opisthosoma, length and width of the propodosomal shield) were identified and suggested for use in identification of male and female Ch. texanus. In male mites of this species, 5 additional parameters were also determined, which describe the length and width of the opisthomal lobes, their ratio, the diameter of the adanal suckers and the distance between them. The morphological features, location and length of 6 setae, which are species-specific in Chorioptes mites, namely 4 setae of the opisthosomal lobe, 1 opisthosomal seta, 1 ventral seta of tarsus III, were described. The parameters of Ch. texanus eggs in the bodies of female mites and on the body of the host animal were determined. The scientific data obtained in this study expand the already existing data on the differential identification of Ch. texanus mites and proves their parasitism in cattle on the territory of Ukraine.