Black wildebeest
Black wildebeest act as hosts to a number of external and internal parasites. A study of the animal in Karroid Mountainveld (Eastern Cape Province, South Africa) revealed the presence of all the larval stages of the nasal bot flies "Oestrus variolosus" and "Gedoelstia hässleri". The first instar larvae of "G. hässleri" were found in large numbers on the dura mater of wildebeest calves, specially between June and August, and these later migrated to the nasal passages. Repeated outbreaks of mange (scab) have led to large-scale extinctions. The first study of the protozoa in blue and black wildebeest showed the presence of 23 protozoan species in the rumen, with "Diplodinium bubalidis" and "Ostracodinium damaliscus" common in all the animals.
Blue wildebeest
The blue wildebeest is susceptible to foot-and-mouth disease, anthrax, sarcoptic mange, and hoof gangrene. The herpesvirus was first isolated from the blue wildebeest in 1960 by veterinary scientist Walter Plowright. Although the causes of death vary from year to year, in one drought in Botswana, young calves and aged females were the most likely to die. On another occasion, an estimated 47% of deaths were caused by disease, 37% were due to predation, and the remainder were the result of accidents.