The Cause and Prevention op Lamziekte. 233 



matter as it does mineral matter. Toxin production may vary with the 

 nature of the tissue, and appears to he more active in tissues such as 

 liver and spleen than in muscle and bone, hut it can occur in any 

 part of a carcass provided the conditions of life of the toxicogenic 

 bacteria are suitable. 



It is more than likely that- protein-rich veo-etable matevial such as 

 beans would also prove to be a good substrate, although this has not 

 actually been tested, and it is not impossible that any dead vegetable 

 matter at all could serve for toxin production provided the requisite 

 degree of anaerobiosis (exclusion of air^ vcere maintained. 

 Fortunately the organism is not parasitic upon the living plant any 

 more than upon the living animal, and altliougli dead vegetation 

 may possibly serve as substrate the dead grasses of grazing areas are 

 too freely permeated by air to be anv source of danger. ^ We should 

 not be surprised, however, if an occasional infection in a silo occurred, 

 and the disease broke out in anv animals which -uere fed upon th ' 

 silage. But such stray happenings would not be reported as lam 

 ziekte and need not be considered. 



The point of importance is that in the lamziekte areas dead 

 animal matter is practically the only source of danger, and that at 

 certain times of the year such carrion can become so violently toxic 

 that although a farin appears to be clean, and no carcasses of large 

 animals can be found, vet the presence of carrion derived from such 

 small animals as lizards, frogs, tortoises, barbels, hares, mierkats, 

 birds, liguans, etc., may be legitimately held responsible for a small 

 outbreak of lamziekte. Indeed, experience has shown that when pica 

 is at its worst during the drougbtv season after the spring rains, the 

 worst cravers amongst a herd will eat such unusual things. Cattle 

 have been actually observed to eat dead barbels, and it is now possible 

 to understand why lamziekte has been definitely associated with pans, 

 in the minds of some farmers. 



The greatest source of danger is. of course, from large -animals 

 dyinc on the veld, wounded game, cattle, sheep, lost lambs, kids, or 

 ostrich chicks: also calves or foals which have been slipped and are 

 not missed at once. Naturally enough, so long as the carcasses of 

 large animals are carefully disposed of. so long will the greatest 

 danger be removed, but so long as the carrion of even the smallest 

 beast of the field is there, so long can a small mortality from lam- 

 ziekte be expected at certain seasons of the year on farms where pica 

 is acute. This mortality mav be negligible during the cold winter 

 months, when such carrion of small animals tends to shrivel up and 

 mummifv rather than to putrefy, but it cannot be altogether dis- 

 counted in the summer. 



The raw material from which the lamziekte toxin is elaborated 

 thus represents the most important link in the etiological chain, and 

 it is there that the first effort should always be made to break the 

 chain. If all carrion is removed, toxin pi'oduction is excluded and 

 the toxicogenic saprophytes will die out altogether in time. It is, 

 however, practically impossible to remove animal debris completely, 

 and some small amounts are sure to be overlooked ; but overlooked 

 carrion becomes non-toxic in course of time by further decomposition 

 and weathering, and although it may certainly remain toxic for six 

 months, or perhaps even a year, it will sooner or later lose its 

 poisonous character. By reducing the general level of veld carrion, 



