Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

aspects of these factors, including pathogen and species overlap, to try and assess the potential
for disease transmission and disturbance of mountain nyala in the northern section of the Bale
Mountains National Park.
Methods
Study area
The study took place in and around the northern section of Bale Mountains National Park, Oromia
NRS in Ethiopia between 1999 and 2000. Mountain nyala are predominantly found in the woodlands
of the northern section of the park and surrounds where Juniper, Hagenia and Hypericum spp.
predominate and also on the open Gaysay grasslands with broad valleys and swampy grassland.
Parasitology
Potential parasites of mountain nyala were identified through faecal analysis and from examining the
parasites of domestic livestock and their potential for transmission. Faecal samples were collected
per rectum from cattle (313) and sheep (300) in Gojera, Soba, Gofingira, Karari and Dinsho kebeles
and preserved in 10% formalin. In addition, 94 fresh faecal samples were collected from mountain
nyala either in the Gaysay or park headquarters areas. The prevalence of parasites eggs and their
density in faeces was then estimated using the Modified McMaster Method as described by MAFF
(1986). In addition, ova culture was carried out by culturing moist faecal samples on a petridish at
room temperature for 21 days. Infective larvae were then recovered using the Baermann Technique
and identified at the genus level at the genus level by the method described by Hansen et al. (1994),
using 10x10 magnification.
Sheep postmortem
An experimental transmission was undertaken to test whether mountain nyala nematodes were
infective to sheep and cattle. A six-month old sheep and a nine-month old calf were treated with
albendazole (5mg/kg Exiptolr, Erfar Pharmaceuticals) to clear all existing nematode infections and
then housed without access to grazing. After 10 days no helminth ova were observed in faeces and
the two subjects were subsequently drenched twice with infective larvae derived from oviculture
from mountain nyala. Larvae collected from the mountain nyala faeces were counted and an aliquot
of 30,000 ml containing 450 larvae was drenched in the first administration. When no ova were
detected in the faeces after 60 days, a second infection was administered after 60 days of 5400 larvae
in 30 ml. Faecal samples were examined from days 30-45 for the presence of nematode eggs, as
above.
Virology
A total of 363 and 470 blood samples were taken from jugular vein of sheep and cattle respectively
from Gojera, Soba, Gofingera, Karari, Dinsho and Kotera villages around the northern Gaysay
<strong>Walia</strong>-<strong>Special</strong> <strong>Edition</strong> on the Bale Mountains 271