PROF. MAINGI NDICHU

Thompson’s gazelles are an important part of wildlife in Kenya and their meat is utilised for human consumption. Gastrointestinal (GIT) parasites however, may be a limiting factor to their management and utilisation. A survey of the prevalence and intensity of gastrointestinal parasites in Thompson’s gazelles was conducted on a game ranch in October 2003. 31 male and female gazelles were captured using net screens. Fecal samples were collected directly from their rectum. Nematode EPG, presence of fluke eggs, cestode eggs and coccidial oocyts were determined on each sample using a modified McMaster technique. All the 31 captured gazelles were shedding strongyle-type nematode eggs and coccidial oocyts. Trichuris eggs were found in only 1 out of 3 fecal samples from the young males and in none of the samples from 6 young females and 22 adult gazelles. Fluke and cestode eggs were not found in any of the samples. Fecal cultures revealed predominance of Haemonchus, Gazellostrongylus and Trichostronglus in fecal samples from the captured gazelles.

The strategic use of moxidectin or closantel in combination with levamisole (LEV) to control gastrointestinal nematodes of sheep in the highlands of central Kenya was examined. Thirty Corriedale female lambs aged between 6 and 8 months were assigned to three treatment groups of ten lambs each. The three groups of lambs were set stocked on separate paddocks for the entire study period of 12 months. Lambs in Group 1 were dewormed strategically with moxidectin at 0.2 mg/kg body weight and those in Group 2 with closantel at 10 mg/kg body weight together with LEV at 7.5 mg/kg body weight. These strategic treatments were given 3 weeks after the onset of both the short and long rains and at the end of the long rainy season. The third group of lambs remained untreated (control group). Nematode infections in the treated groups of lambs and larval infectivity for the pastures on which the lambs were grazing were well controlled compared with the untreated control group. This resulted in higher weight gains and packed cell volume (PCV) in the treated lambs compared with the untreated lambs. These parameters were comparable between the lambs treated with moxidectin and those treated with closantel plus LEV. The estimated monitory benefit per animal from the control of gastrointestinal nematodes using moxidectin or closantel in combination with LEV when compared with animals in the control group were US dollars 26 and 25, respectively. It was concluded that worm control strategies for sheep in the study area, which are based on anthelmintic treatments during the rainy seasons, are effective. Due to the extended period during which pastures remain infective in the high rainfall central highlands of Kenya, anthelmintics with sustained action such as moxidectin or closantel may be most effective. On farms where resistance to the commonly used benzimidazoles or LEV groups of anthelmintics has developed, moxidectin or closantel may be used in helminth control programs for sheep.

Haematological data were obtained through analysis of blood samples taken from sixteen donkeys randomly selected from a donkey population in Kiambu District, Kenya. Nine out of sixteen of the donkeys examined were anaemic, with low RBC counts (ranging between 3.2 - 4.18 x 106/ml) and low Hb concentrations (ranging between 6.6 - 9.7 gm%). Seven out of nine of these donkeys in addition, had relatively low PCV values (18% - 28.7%). The epg counts in the anaemic donkeys ranged between 0 and 3100. The total protein levels in all the sixteen donkeys were slightly elevated. The differential leucocyte counts were within the normal range in twelve out of sixteen donkeys. Two donkeys had leucocytosis, with WBC counts ranging between 18.6 and 24.8, and epg counts ranging between 100 and 200