Susceptibility to IVM (IVM) of “strain A” Haemonchus contortus which had been exposed to IVM four times over a 2-year period was compared to IVM susceptibility of “strain C” H. contortus which had no prior field exposure to IVM, by in vivo and in vitro methods. In vivo, the percentage reduction in faecal egg counts (FEC) and the total worm counts (TWC) were compared between control animals (lambs and kids) and animals treated with low dose IVM (20 μg/kg). In vitro susceptibility to IVM was evaluated by larval migration inhibition (LMI) after the two strains of H. contortus were exposed to different concentrations of IVM. The dose response, measured as the proportion of larvae inhibited from migrating, was used to estimate LD50. Although differences in response to IVM in the in vivo determinations were not significant, “strain A” H. contortus had a significantly higher LD50 than “strain C” in the LMI assay. Coincident with the conduct of the in vivo experiment, it was observed that “strain A” H. contortus established and survived better than “strain C” in the control lambs.

A survey of gastrointestinal and other internal parasites was conducted on apparently healthy indigenous chickens of both sexes obtained from open-air markets around Nairobi, Kenya. A total of 131 birds from 9 districts were examined. Worm egg and coccidial oocyst counts were performed on faecal materials from each bird while worms collected from gastrointestinal tracts were quantified and identified. Many chickens had gastrointestinal helminths (90%), but only a few of these (13.9%) had coccidial oocysts. Nematodes were the predominant helminths (89%) followed by cestodes (51.5%), but no trematodes were recovered. The nematodes recovered were: Heterakis isolonche (59.5%), Subulura brumpti (36.0%) Tetrameres spp. (32%), Ascaridia galli (19.8%), Gongylonema ingluvicola (19.1%), Acuaria hamulosa (6.1%), Heterakis gallinarum (5.3%) and Capillaria spp. (2.3%). The cestodes recovered were: Raillietina echinobothrida (37.7%), Hymenolepis carioca (33.6%), Davainea proglottina (6.9%), R. tetragona (6.1%) and R. cesticillus (2.3%). Other endoparasites encountered were the air-sac mite, Cytodite nudus (15.3 %), Sacocystis spp. (5.6 %) and Syngamus trachea (4%). The mean caecal worm counts in chickens were significantly different (p < 0.05) in various districts. However, there was no significant difference in the overall worm loads between sexes (p > 0.05). The results of this study showed that there is heavy parasitism with various endoparasites in apparently healthy traded indigenous chickens in Kenya

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.