Infections of the gastro-intestinal tract

Physocephalus sexalatus is a spirurid nematodes that utilizes an intermediate host, usually a dung beetle, in its life cycle. It occurs in the stomach of warthogs and bushpigs and only when present in massive numbers do they cause gastritis.

The genera Oesophagostomum and Murshidia (Fig. 29) are large genera that contain numerous species and that are particularly abundant in elephants, rhinoceroses and wild pigs. Six species of Oesophagostomum, of which Oesophagostomum mocambiquei and Oesophagostomum mwanzae were the most common, and two of Murshidia have been described from the large intestine of warthogs and bushpigs and were present in vast numbers. An average of 35 000 for the former and 16 725 for the latter nematodes were recovered, a total of almost 52 000 worms per animal (Horak, Boomker, De Vos & Potgieter, 1988; Boomker, Horak, Booyse & Meyer, 1991b). Clinical oesophagostomosis was not reported and macroscopic lesions were limited to a few petechiae in the caecum and colon (Boomker, unpublished data, 1989).

Ascaris phacochoeri was constantly found in surveys done in different parts of South Africa, and its prevalence varied from 30.7 to 57%. No reports of this nematode causing disease in free-living warthogs and bushpigs could be found.

The anoplocephalid tapeworms Moniezia mettami and Paramoniezia phacochoeri are regularly encountered in young warthogs, in which they do not cause disease. The same applies to the trematode Gastrodiscus aethiopicus, which is also found in zebras.

Fig. 30: The anterior part of Murshidia hamata illustrating the strongly developed oesophagus and head that is clearly set off from the rest of the body.