Haemonchus contortus from the vaal ribbok, Pelea capreolus, and the bontebok, Damaliscus dorcas dorcas, in the Bontebok National Park.

During a survey of the parasites of antelope in the Bontebok National Park, Swellendam, Cape Province, specimens of Haemonchus contortus with exceptionally long spicules were recovered from 5 out of 8 bontebok, Damaliscus dorcas dorcas, and 3 out of 5 vaal ribbok, Pelea capreolus, but not from 4 springbok, Antidorcas marsupialis. Typically, H. contortus has spicules 0,466 +/- 0,085 mm long, but those recovered from vaal ribbok had spicules 0,581 +/- 0,02 mm long and were recovered in large numbers from this antelope only. This indicates that the nematode is probably a definitive parasite of vaal ribbok, and its occurrence in bontebok must be regarded as accidental.