Kovalenko S. Chorioptic mange of cattle (prevalence, diagnosis and control measures)

The dissertation summarizes the results of research on the distribution, diagnosis and control measures for chorioptosis in cattle in the territory of Poltava and Kharkiv regions of Ukraine. The conducted studies established that the average extensiveness index (EI) of chorioptous invasion of cattle in the conditions of livestock farms of the surveyed area is 21.23 %, and the intensity of infection (II) is 60.48±2.19 individuals/4 cm2, ranging from 2 to 307 ind./4 cm2. Farms of the Kharkiv region were more affected by bovine chorioptic mange, there the EI is 27.05 %, and the II is 71.93±4.32 ind./4 cm2. In farms of the Poltava region, the average EI is 16.80 % and the II is 53.81±3.53 ind. /4 cm2. New data were obtained on the peculiarities of the course of chorioptosis as part of mixed infections in cattle. It was established that that acariasis occurs more often in mixed infections (68.10 %). As monoinvasion it was less frequently diagnosed (31.90 %). A total of 23 types of mixed infections were detected, among which two-component (51.97 %) and three-component (32.68 %) mixed infections were detected more often, and four-component (14.17 %) and five-component (1.18 %) ones were less common. The most common co-members of Chorioptes mites were parasitic insects Bovicola bovis (40.16 %), gastrointestinal nematodes of the Strongylida order (31.10 %), namely Strongyloides papillosus (29.13 %) and Trichuris spp. (25.19 %). Less often, co-members of Chorioptes mites were the protists Eimeria spp. (19.29 %), cestodes Moniezia spp. (13.78 %) and trematodes of the family Paramphistomatidae (5.91 %). Peculiarities of age and seasonal dynamics of chorioptosis in cattle were studied. The rates of chorioptic mange gradually increase with the age of its hosts. Cows are most susceptible to the disease (EI 30.45 %, II 94.04±5.00 ind. /4 cm2). The seasonal dynamics of chorioptic mange is characterized by the highest extensiveness index and intensity of infection in winter (30.83 % and 62.19±4.64 ind./4 cm2) and spring (28.33 % and 61.85±5.28 ind./4 cm2). The minimum rates of infestation of cattle by Chorioptes were established in summer (10.83 % and 27.23±3.11 ind./4 cm2) and autumn (21.67 % and 36.58±2.97 ind./4 cm2). The level of contamination of livestock facilities with Chorioptes mites depends on the utilized husbandry practices. For untethered animals, the maximum values of the extensiveness index and index of contamination intensity were found in litter from places where the animal hosts lie (100 % and 257.50±18.81 ind./kg), scrapings from objects that animals scratch (100 % and 194.38±10.59 ind./kg) and litter collected from the center of the room (90 % and 80.56±11.62 ind./kg). For tethered cattle, the indicators of environmental contamination turned out to be lower and were maximum when examining the litter and scrapings from litter located in the area of the hosts’ heads (45 % and 90.28±20.39 ind./kg). The severity of the clinical manifestation of bovine chorioptosis depends on the rates of the intensity of infection. Thus, at a low intensity of chorioptosis (up to 60 ind./4 cm2), the clinical signs in cows were characterized by skin lesions in the area of the tail base and disheveled hair (100.0 %), itching (85.10 %), and the appearance of scales and scabs (87.24 %), thickening and wrinkling of the skin, drying of skin (17.02 %), violation of the skin integrity with leakage of exudate or blood (53.2 %) with different degrees of their manifestation. At the average intensity of chorioptic mange (from 60 to 170 ind./4 cm2), the clinical course was characterized in 88.24 % of cows by skin lesions in the area of the tail base, in 91.18 % by disheveled hair, in 85.29 % by itching, in 76.47 % by scales and scabs. With a high intensity of chorioptosis (II more than 170 ind./4 cm2) in cows, the clinical course was largely manifested by signs of skin lesions at the tail base and buttock humps (100 %). Also, in 100 % of cases, the acariasis was manifested by itching and raggedness of the hair cover at the damaged skin areas. In 95.24 % of cows, chorioptosis was manifested by damage of skin near the hind quarter of udder and the appearance of scales and scabs on the skin, in 85.71 % by thickening, folding and drying of the skin, in 76.19% by a violation of the skin integrity with leakage of exudate or blood, in 52.38 % by alopecia, in 42.86 % by redness of the skin in the affected areas, in 33.33% by skin lesions on the neck and shoulder blades. It has been established that chorioptic mange significantly affects growth and development of young cattle.