Prevalence and biodiversity of helminth parasites in donkeys (Equusasinus) in Iran

There are over two million equine animals in Iran, of which approximately 75% are donkeys. Despite this, very little is known about their parasite status and the impact of this on their work output. Usually, it is the alimentary canal, body cavity and liver that harbor parasites in equine species. In this study, 45 donkeys (Equusasinus) were examined at necropsy. The contents of the stomach, small intestines and large intestine were washed separately and examined for helminth parasites. Their livers were sliced into 1×3cm pieces, squeezed in warm water and examined for helminths. The skin, eyes and all other internal organs underwent a search for parasites. Twenty-two species of nematodes were identified, which included one species of cestode, two species of trematodes and one species of gastrophiliid. The species included ascaridae(×1), atracidae(×1), oxyuridae(×1), trichostrongylidae(×1), spiruridae(×1), anoplocephalidae(×1), fasciolidae(×1) dicrocoeliidae(×1), gastrophiliidae(×1), strongylinae(×3), habronematidae(×3), and cyathostominae(×12). The most abundant group with regards to the number of species and their intensity of infection was Cyathostominae (small strongyles), in which Cylicocylusnassatus and Cyathostomumtetracantum were the most prevalent and abundant species. Strongylus vulgaris was the commonest species among the large strongyles.Of the three species of Habronema, H. muscae was the most prevalent species, followed by H. majus and D. megastoma. Probstmayriavivipavra was collected from 20% of donkeys, and more than 450,000 worms were collected from a single animal. Gastrophilusintestinalis was collected from 66.6% of the donkeys that were examined in this study. The prevalence and intensity of the other helminths were low. The presence of mixed infections was the rule in this study, as this was found in all 45 donkeys. The consequent effect of such infections on the health of donkeys needs further investigation.