Parasitism of Cattle Ticks (Ixodidae) in Tiaret, Algeria

In order to better understand the problem of damages and diseases transmitted by ticks (Ixodidae) to cattle in Algeria, the author studied the seasonal features of their parasitic activity in the region of Tiaret (Algeria). From January to December, in a sample of 1240 cattle examined, 368 were infested by ticks, with a global cattle infestation rate of about 30%. The maximum monthly parasitic burden was five ticks per animal. Among 3975 ticks collected, 13 species were identified, with six species of the genus Hyalomma (66%) and three of that of Rhipicephalus (31%). The numerically dominant species was H. lusitanicum (20%), whereas H. excavatum and H. marginatum marginatum had the highest cattle infestation rates (13%). The three monotropic species, recognized as vectors of bovine piroplasmosis in Algeria, represented 37.4% of the total tick population. Among these, Rhipicephalus bursa represented 69%, Hyalomma detritum 28%, and Boophilus annulatus 3%. The semiarid climate of the region must have been less favorable to B. annulatus. The presence of R. bursa was shown to be all year round, whereas that of H. detritum was limited to about four months, because of a more prolonged wintry diapause of its preimagos. R. bursa predominance indicated that babesioses must have occurred more frequently in the region than theileriosis (caused by Theileria annulata). The low tick burden observed and the numerous cases of piroplasmoses reported in cattle underlied the presence of an enzootic stability problem towards these diseases. Because of a potential infection risk during some periods of the year, notably in imported animal breeds, owing to adult tick predominance in the hot season and preimagos in the cold season, a preventive acaricide treatment can be applied in May and October