Prevalence of Libyostrongylus douglassii in commercially reared ostriches in the highveld region of Zimbabwe

A total of 435 freshly dropped faecal samples were collected from 11 randomly selected ostrich farms during September and November 2002 to determine the prevalence of Libyostrongylus douglassii (ostrich wireworm) in the highveld region of Zimbabwe. Samples, which consisted of 339 samples from breeder birds and 96 samples from pre-slaughter grower birds were screened for nematode eggs using the modified McMaster technique before being individually cultured in an incubator at 28 degrees C. Cultures were examined for the presence of L. douglassii third stage larvae (L3). Using faecal egg counts, eight of 11 farms (72.7%) were positive for L. douglassii in breeders but no eggs were detected in the growers. The faecal culture method detected wireworm larvae in the breeding stock of all farms that were surveyed (100%) and five of the eight farms (62.5%) which had grower birds. Libyostrongylus douglassii was detected in all farms (100%) based on the faecal culture method. Libyostrongylus douglassii was detected for the first time in 7 of 11 farms (64%) surveyed. Data from questionnaires designed to assess farm management practices showed that four out of seven (57.1%) of the ostrich producers were unaware of the importance of wireworms in ostriches. The farms did not have a regular deworming programme for their birds and no faecal samples were sent routinely to the veterinary laboratory for screening of wireworms. Wireworm infections were not taken into consideration by farmers during buying and selling of birds.