- Geeldikkop : Experimental induction by feeding the plant Tribulus terrestris L.
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GEELDIKKOP: EXPERIMENTAL INDUCTION BY FEEDING THE PLANT TRIBULUS TERRESTRIS L. (ZYGOPHYLLACEAE)
E. M. VAN TONDER, P.A.BASSON AND I.B J. VAN RENSBURG
For the first time since the work of Theiler (1918) and Quin (1928, 1929), geeldikkop has been successfully produced in various feeding experiments where Tribulus terrestris was used in order to assess the significance of this perennial plant as a possible aetiological agent of the disease. The results obtained afford convincing evidence that the ingestion of T. terrestris during certain seasons can cause geeldikkop. The latent period varied from 3 to 34 days with an average of 13 days. Although the precise mechanism is still unknown, it is evident that a toxic substance, be it an unstable aberrant metabolite or a mycotoxin within the plant or in adhering fungal spores on its surface, is responsible for a syndrome of photosensitization and icterus. The lesions observed correspond to those of natural cases and the most significant ones to those reported by Theiler. Of these lesions, the most characteristic one is the presence of a crystalloid cholesterol-like material (and the clefts left behind when it has been dissolved during processing) in hepatocytes, Kupffer cells and within bile ducts, frequently occluding them. A brief history of the incidence of the disease on the farm Grootfontein in the district of Middelburg, Cape, is given and details of the outbreaks on this property during 1971 are discussed.
Journal South African Veterinary and Medical Association 43 (4)