Occurrence and Risk Factors of Endoparasites and Associated Lesions in Donkeys in Selected Abattoirs in Kenya

Abstract

The donkey is a significant animal species in the arid and semi-arid areas, it serves as an important means of transport and provision of draught power. Gastrointestinal parasites and hemoparasites have been reported to cause the most prominent diseases in donkey as compared to other diseases. Helminth infestation has been reported to cause mortality in Ethiopia besides retarding growth, decreasing work output in addition to distress and pain. Recent studies to show the diverse nature of gastrointestinal parasites and their pathological effects have not been done in Kenya. A survey was done in order to determine the diversity and intensity of donkey endoparasites and to characterize associated lesions in selected abattoirs in Kenya. Three abattoirs (Kinamba, Mogotio and Lodwar) were visited between July-September, 2017. A total of 282 donkeys presented for slaughter were systematically sampled for gastrointestinal parasites and associated lesions. Blood, fecal, parasite and gastrointestinal organ samples were collected and screened for hemoparasites, quantification of the fecal eggs, identification and characterization of pathological lesions respectively. The diverse nature of gastrointestinal parasites and hemoparasites were determined by virtue of their morphological characteristics whereas the intensity was assessed by quantifying the fecal egg count using the McMaster technique. The pathological lesions were characterized grossly and microscopically. Adults helminths parasites identified were; Anaplocephala magna 2.5%, Anaplocephala perfoliata 10.3%, Cylicocyclus auriculatus 2.1%, Cylicocyclus leptostomus 0.4% Cyathostome species 2.1%, Parascaris equorum 20.2% , Strongylus edentatus 12.1%, Strongylus equinus 0.4%, Strongylus vulgaris 52.8%, Setaria equina 3.5% and Triodontophorus serratus 0.4%. Fifty one point eight percent were positive for Gasterophilus species larvae with an occurrence of 38.3%, 5.7% and 7.8% for G. intestinalis, G. nasalis and G.pecorum respectively. Forty four point seven percent of the donkeys were positive for xiv strongyle eggs; Parascaris equorum at 5.3%, Oxyuris equi at 1.1%, Triodontophorus tenuicolis and Habronema species each at 0.7% and cestodes eggs at 0.4%. For intensity determination, 55.3% had no eggs present, 39% had a low infection (up to 500 EPG), 5% had a medium infection (501-1000EPG) with 0.7% having a high infection (>1000 EPG). For the hemoparasites, Anaplasma phagocytophilum occurred at 2.5%, trypanosomes at 5.6%, Babesia caballi at 2.5% and microfilaria at 0.60% of the examined donkeys. Pathological changes observed in the stomach mucosa included diffuse areas of erosion after dislodging the various Gasterophilus species. Microscopic observations made included disruption of the keratinized layer of the non-glandular portion of the stomach, yellowish discoloration of the epithelium, loss of keratin and thickening in some areas. In the liver, hepatomegally was observed in 6% of the donkeys and a cyst-like focal swelling measuring 2-3 cm in diameter protruded above the capsule in 3% of the donkeys. The other 3% had pinpoint necrotic foci on the hepatic parenchyma. Microscopically, there was a well demarcated zone comprising fibrous connective tissue, hemosiderosis and cellular infiltration. In the intestines, focal nodules were present in 3% of the donkeys. Microscopic examination revealed disruption of the mucosal lining and nematodes larvae encapsulated in the sub mucosa. Intestinal ulcerations were observed in 2.5% of the donkeys and were mainly characterized by circulatory disturbances and cellular infiltrations. The survey revealed that up to 86% of the donkeys in Kenya are infested by a variety of gastrointestinal helminths and 11.3% by hemoparasites. Gastrointestinal parasites may cause severe pathological lesions in the gastrointestinal tract and these interfere with digestion and assimilation of nutrients thereby leading to poor work performance of the donkeys. There is need to control these parasites in donkeys in Kenya.