Epidemiological studies on gastrointestinal helminths of dromedary ( Camelus dromedarius) in semi-arid lands of eastern Ethiopia

Abstract

A total of 752 dromedaries were examined and 75% were found to be harbouring nematode eggs. The mean EPG was 1831 and the range was from 100 to 21,200. The prevalence rates in the four-age groups examined were 59.6% (3–7 years), 72.4% (8–12 years), 76.1% (13–17 years) and 83.9% (18–22 years). The prevalence rate for females and males were 77.6 and 64.8%, respectively and for long dry, short rainy, short dry and long rainy seasons were 66, 80, 69 and 82.6%, respectively. The mean EPG of faeces was significantly ( P<0.01) higher for older animals compared to other group of younger animals (3–7 years), for females compared to males, and for rainy compared to dry season. Sixteen dromedary gastrointestinal organs were used for identification and counts of helminths. Among the adult worms identified, from the abomasum, Haemonchus longistipes had a 94% prevalence rate. From the small intestine Trichostrongylus colubriformis, Trichostrongylus probolurus, Impalaia tuberculata and Strongyloides papillosus were identified with prevalence rates of 75, 25, 63 and 20%, respectively. Moreover, cestodes such as Moniezia benedeni, Moniezia expansa, Avitellina spp. and Stilesia globipunctata with prevalence rates of 31, 13, 25 and 19%, respectively, were identified. I. tuberculata was identified for the first time in this country from a dromedary. The pathological lesions were more pronounced in higher infestations. Infestation level over approximately 1000 of H. longistipes and 15,000 in mixed infection of T. colubriformis and I. tuberculata, caused gross lesions of ulcerated and hyperaemic mucosa, and the odour of the fluid were fetid. The microscopic lesions observed were sloughing of epithelium, necrosis of glands, atrophy and loss of villi, haemorrhages and cellular infiltration mainly of eosinophiles and lymphocytes.