| dc.description.abstract | This study was designed to investigate the prevalence gastro-intestinal nematodes,
gross skin conditions and ectoparasites in Mwingi District, Kenya. The associations
between known management and husbandry risk factors and donkeys nematodiasis were
assessed. The effectiveness of ivermectin R against the nematodes was evaluated.
Faecal sampling was done on 254 donkeys randomly selected from 186 herds.
These donkeys were also examined for presence of ectoparasites and gross skin lesions
and their body conditions and ages determined. Information on donkey management and
husbandry practices on 168 farms was gathered using on-farm visit questionnaires.
McMaster technique was used to determine the nematode egg counts per gram
(epg) of faeces. Samples positive for nematode eggs were cultured and the larvae
characterised. Similarly, all the ticks were characterised. The skin scrapings were
examined for mites and cultured for fungi.
Fifty and thirty donkey farms in Kyuso and Mwingi divisions respectively were
used in evaluating the effectiveness of Ivermectin R. Pre-treatment faecal sampling was
done before administering Ivermectin R subcutaneously at 200 micrograms per kilogram
body weight. Drug effectiveness was determined as percent faecal egg reduction between
the pre- and post-treatment egg counts.
A donkey herd was considered positive for nematodiasis if the epg for at least one
of its donkeys was above five hundreds. Descriptive statistics, analysis of variance, t-test,
Mann- Whitney test, logistic regression and discriminant analyses were performed on the
data.
Eighty three percent of the herds had nematodiasis. The mean egg counts for
Mwingi and Migwani statistically (P < 0.05) differed from those of Kyuso and Mumoni.
There was no statistical ( P > 0.05 ) difference between the division-specific means of
epg for Mwingi and Migwani and between those of Kyuso and Mumoni.
The sex of the owner, average age of the herd, deworming status, the level of
hygiene in the holding premises and farm location (division) were marginally (P < 0.1)
associated with nematodiasis. Donkey herds that belonged to women or were kept in
"dirty" bomas or were not dewormed had high risks for nematodiasis, with odds ratios
of 14.6, 3.92, and 3.82 respectively. Donkey herds whose average age was above two
years had a marginal (OR = 2.3) risk for nematodiasis. An overall correct classification
of 67% of herds having nematodiasis herds was achieved using discriminant analysis.
The herd cases in Mwingi, Migwani and Mumoni overlapped on the scatter plot while
those in Kyuso were clearly differentiated from the rest.
Strongylus vulgaris, S. edentatus, S. equinus, Cyanthostomum coronatum, C.
tetracanum, C. radius, Strongyloides species and ascarids were the gastro-intestinal
nematodes that affected the donkeys.
The pre-treatment mean epgs for Kyuso and Mwingi did not statistically (P >
0.05) differ. Ivermectin R was highly effective ( > 99%) in both divisions. Results of
both t- and Marin-Whitney tests for assessing the within division drug efficacy were
highly significant (P = 0.00001). There were no statistical (P > 0.05) differences
between the drug effectiveness for the pre- and post-treatment epgs at the division and
herd levels.
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Twenty three percent of the study herds did not have ectoparasites. Overall herd
tick prevalence was 77 %. Seventy four percent of these herds had Rhipicephalus
pulchellus, 13% had Rh. appendiculatus and 13 % had both Rh. pulchellus and Rh.
appendiculatus. No other ectoparasites were observed. Wounds, overgrown hooves,
alopecia and combinations of these were the gross skin lesions observed. Overall, twenty
out of twenty two (96%) skin scrapings were positive for fungi. Of these fungi, 80%
were Trichophyton spp, 5% Epidermophyton spp, 5% Microsporum species.
Based on these findings, prospective studies should be designed to establish the
bionomics and infection patterns of donkey gastro-intestinal nematode larvae, determine
the impact of gastro-intestinal nematodes on donkey health and performance, clinically
evaluate other affordable antihelmintics and attempt to isolate the active ingredients in
the herbal preparations used to treat donkey worms in Mwingi District. | en |
