Comparison of the efficacy of three anthelmintic Drugs against mixed natural Gastrointestinal Nematode infections in Camel(camelus dromedarius) in Kenya
This study was undertaken to identify the types of helminth parasites in camels, their prevalence rates in different seasons, the effects of age and sex of camels on helminth infestation rates and to compare the efficacy of three anthelmintics, namely albendazole, levamisole and thiophanate in the treatment of gastrointestinal nematodes in camels (Carne/us dromedarius) owned by the local community in Lorroki Division, Samburu District, Kenya. During the survey, 255 camels had their faecal samples taken once over a period of five months. These included 59 camels in November 1992, 66 in December 1992, 47 in January 1993, 46 in February 1993 and 37 in March 1993. The faecal samples were subjected to the McMaster egg counting technique and coproculture. The worm eggs and recovered nematode larvae were identified using standard parasitological techniques. Blood was collected in heparinized capillary tubes for determination of the packed cell volume (peV) which was used as an indicator of the anemia status. Examination of the buffy coat and blood smears was done to rule ou t the presence of haemoparasi tes. Out of the 255 camels examined as previously described, 76 clinically healthy camels but which had moderate to heavy worm egg counts (EPG of more than 400) were selected and used in the anthelmintic drug study. These camels which included both males and females comprised all age groups. pev values for all the animals was determined once. before and one mon th after treatment. The selected camels were randomly distributed (n=19) by age, sex, EPG counts and household into three treatment and one control group. The survey on helminthiasis showed that peak strongyle worm egg counts in this area occur during and soon after the rains. Calves and adults had higher worm egg counts than immatures. When assessing the effects of sex on worm egg burdens, it was found that female camels had higher (p < 0.05) worm egg counts than males. The data showed that 80% of all eggs that were identified were those of strongyle nematodes. Other parasite eggs identified included those of tapeworms (especially Moniezia spp), Strongyloides spp, Trichuris spp. and Fasciola spp. Larval culture and identification showed that Haemonchus spp and Trichostrongylus spp were the most common and probably the most pathogenic gastrointestinal helminths of camels in this area. Other nematode parasites identified included Cooperia spp, Bunostomum spp, Oesophagostomum spp, Strongyloides spp and Ostertagia spp. When assessing the efficacy of the three drugs studied, it was found that the mean rcv values in all the treated camels were significantly higher (p < 0.05) than those of the untreated controls one month after treatment. The present study indicates that thiophanate at a dose of 60 mg/kg body weight was the best drug as shown by the significant reduction in the post-treatment nematode worm egg counts. Albendazole at a dose of 10 mg/kg and levamisole (at a dose of 10 mg/kg) came next in that order with levarnisole being the least effective. This study reports, for the first time, the presence of Fasciola spp in camels in Kenya. It also indicates that peak worm infestations occur mostly during the rain season and that Haemonchus spp is the most common GIT parasite in camels.The study also showed that thiophanate and albendazole promise to be highly effective, safe and fast acting drugs for use in treating nematode infections in camels of all ages.