Thelazia rhodesii in the African Buffalo, Syncerus caffer, in Zambia

ABSTRACT

We report 2 cases of Thelazia rhodesii infection in the African buffaloes, Syncerus caffer, in Zambia. African buffalo calves were captured from the livestock and wildlife interface area of the Kafue basin in the dry season of August 2005 for the purpose to translocate to game ranches. At capture, calves (n=48) were examined for the presence of eye infections by gently manipulating the orbital membranes to check for eye-worms in the conjunctival sacs and corneal surfaces. Two (4.3%) were infected and the mean infection burden per infected eye was 5.3 worms (n=3). The mean length of the worms was 16.4 mm (95% CI; 14.7-18.2 mm) and the diameter 0.41 mm (95% CI; 0.38-0.45 mm). The surface cuticle was made of transverse striations which gave the worms a characteristic serrated appearance. Although the calves showed signs of kerato-conjunctivitis, the major pathological change observed was corneal opacity. The calves were kept in quarantine and were examined thrice at 30 days interval. At each interval, they were treated with 200 microg/kg ivermectin, and then translocated to game ranches. Given that the disease has been reported in cattle and Kafue lechwe (Kobus lechwe kafuensis) in the area, there is a need for a comprehensive study which aims at determining the disease dynamics and transmission patterns of thelaziasis between wildlife and livestock in the Kafue basin.