Efficacy of an in-feed formulation containing ivermectin for the control of intestinal strongyles in captive zebras (Equus burchelli (Gray, 1824))

The efficacy of medicated food pellets (containing 10 mg of ivermectin per kg, UNIFEED, Veronesi, Verona, Italy) was evaluated for the control of intestinal strongyles in a group of captive zebras (Equus burchelli) at the Safari Park, Fasano (Apulia region, Brindisi Province, southern Italy). The egg reappearance period and the faecal egg counts in terms of eggs per gram of faeces were investigated. From day 0 until day +9, 30 zebras were fed with medicated pellets and pooled faecal samples were collected from the floor of paddocks. The drug showed an efficacy of 100% for up to 78 days post-treatment, with one exception. Strongyle eggs collected prior to the treatment were used to perform coprocultures and larvae harvested were molecularly identified as Cylicostephanus minutus and Cylicocyclus leptostomum with a reverse line blot hybridization assay. The administration of ivermectin with medicated food pellets was effective in controlling intestinal strongylosis in captive zebras. The opportunity to treat captive ungulates with an in-feed anthelmintic is discussed in relation to the fractious nature of these animals, which often impairs helminth control programs in zoo-parks.