Clicky

Author: Prof Joop Boomker

Introduction

When considering the helminths of wildlife one should first define what exactly wildlife is. Some will say, only the mammals, others will include the fish and the reptiles, still others everything that is not kept behind bars. In South Africa the helminths of wildlife, in this case many of the antelope species, and some of the pachyderms, carnivores and fishes have been systematically surveyed, but not those of the amphibians, reptiles, rodents and, especially, the birds. Considering the diversity of the wildlife of Africa, the second largest continent of the world, we really know very little about the helminths that affect them and even less about the diseases caused by helminths. Animals that die of helminthoses are quickly devoured by scavengers, especially in the larger nature reserves, and data on the cause of death and the necropsy findings are therefore not available.

Another complicating factor is that the study of helminth biodiversity is an invasive process which is frowned upon by ecologists, game reserve managers and animal rights activists. Because parasites are internal it is not possible to remove them and leave the host alive, and artificial media for maintaining parasitic larval and adult stages are not in common usage.

For many years helminths of mammals have been collected incidentally, usually during hunting expeditions and incidental post mortem examinations, and from road kills. Until about 1940 numerous helminths new to science were described and the life cycles of several elucidated. During the years of the second world war and for a considerable period thereafter, the emphasis shifted to investigations of the pathogenic effects of helminths of domestic animals, and thus away from the helminths themselves. Helminths of wildlife received little attention and only a few new species or isolated, interesting cases were reported. From about 1973 onwards there was a renewed interest in the helminths of wildlife. Conservation authorities made material that would otherwise have been discarded or ignored available to scientists of various disciplines, who advise the conservation authorities of their results and assist them with better management of existing conservation areas.

Round’s “Check list of the helminth parasites of African mammals of the orders Carnivora, Tubulidentata, Proboscidea, Hyracoidea, Artiodactyla and Perissodactyla”, which appeared in 1968, is still the only relatively complete and fully annotated check-list but, particularly in East and South Africa, numerous additions have since been made.