The Cause and Prevention of Lamziekte. 231 



of speedy dissolution, are absent, and both temperature and humidity 

 are against rapid putrefaction,. Furthermore, the absence of larvae 

 to ensure toxic infection throughout the whole cadaver, and of the 

 bknv-ilies themselves to act as meclianical carriei's from carcass to 

 carcass, throws the onus of infection upon soil and dust, and so leaves 

 greater opportunity for ordinary non-toxic putrefaction wherever the 

 soil is not heavily infected and aerial spores are infrequent. Some- 

 times such carcasses are toxic in one part and non-toxic in another, 

 indicating a localized rather than a generalized infection with the 

 toxicogenic saprophyte. 



As another instance of the influence of weather upon the toxicity 

 of carrion may be cited the observation that carcasses are less toxic 

 after lieavy rains, particularly old carcasses of which the skeleton is 

 the major portion. Tlie most poisonous parts of ibe residual putre- 

 fying soft tissues are washed down into the soil, the carcass remnants 

 are ])artially leached out and aerated, and conditions tend to be 

 created for the dominance of a more aerobic flora which is not only 

 subversive of the interests of the anaerobes, but which may possibly 

 tend to destroy the preformed toxin. The bleaching and 

 " sweetening " of toxic bones is hastened by the leaching and 

 aerating action of rains, and the toxicity steadily falls off with time. 

 Tlie influence of rains may possibly have another effect merely in 

 virtue of the water conveyed to the carcass. From laboratory experi- 

 ments it would appear that toxin production is much less marked in 

 liquid than in semi-solid media, although this perhaps depends upon 

 the quantity of substrate as well as the quantity of water. Whatever 

 be the explanation, the fact remains that carrion is rendered less toxic 

 by the weathering action of rain. 



The seasonal variation of toxicity of carcass material is of great 

 importance in connection with the control of lamziekte, especially in 

 relation to the seasonal variation of '' osteophagia " {mde infra). 



Returning to the spread of the causal organism, we may regard 

 the long-distance carriers as birds and moving stock ; to a less extent 

 dogs or jackals, and wind laden with dust. Dogs and jackals 

 carrying bones and carcass material, are certainly responsible in some 

 cases for carrying infection from place to place on the same farm 

 and to neighbouring farms. S])ores may also be distributed through 

 their faeces. 



The spread of the actual spijres is to some extent analogous to the 

 spread of anthrax spores, but there are important differences arising 

 from the fact that anthrax is an infectious disease in the ordinary 

 sense of attacking the live animal, while lamziekte is not, strictly 

 speaking, an infections disease at all. It is simply a ptomaine 

 poisoning of saprophytic origin, and only affects certain species of 

 animals under certain sjiecified and localized environmental condi- 

 tions. Tf it ever became desirable to biing it within the 

 scope of an Infectious Diseases Act it might be sclieduled in popular 

 language as infectious, but in the scientific sense it is no more an 

 infectious disease than is botulism or ergotism, both of which spread 

 by infection — of dead matter in the former case, and of the living 

 plant in the latter. 



"We know, however, that a beast can carrv the causal Imcteria in 

 its intestines, and that these can multiply as soon as the animal dies; 



