786 MICROBIOLOGY dF DISEASES OF MAN AND DOMESTIC ANIMALS 



growth of and consequent absorption of toxic principles from the 

 infective agent lodged primarily in the small intestine, and secondarily 

 in the liver and other organs bf the body. 



The disease appears to be peculiarly an American one, and has been 

 reported at interVals for many years from several of the Middle Western 

 States and Kentucky, Tennessee, Virginia and North Carolina, and 

 more recently from New Mexico. The bacterium. Bacillus lactimorbi, 

 regarded by Jordan and Harris as the causative agent, appears to 

 flourish chiefly in the moist, shaded pasture lands of creek bottoms, 

 or, as in New Mexico, on pasture lands that are subject to irrigation or 

 flooding. 



Bacillus lactimorbi is an aerobic, spore-bearing, non-liquefying, non-gas-forming 

 microorganism, which, when stained with LoefBer's methylene blue, shows one or 

 more metachromatic granules within its body. In young cultures it is Gram- 

 positive, slowly alkalinizes milk, which at times becomes clarified through the great 

 accumulation of hydroxyl ions. Agar plate colonies resemble those of streptococcus, 

 and there frequently is developed a delicate film growth over the plate. It, or 

 members of its group, are seemingly widely distributed in nature, as Luckhardt 

 has found bacteria practically identical with Bacillus lactimorbi on alfalfa obtained 

 from Wisconsin, Illinois and Indiana, as well as on plants of several species from 

 New Mexico. Certain of these strains possessed pathogenic properties, others 

 showed none; therefore, it is believable that the bacterium itiay, under peculiar 

 environmental conditions, develop varying degrees of virulence and pathogenicity. 

 It may be properly regarded as a facultative pathogen. 



Pathogenicity is demonstrable for young rabbits, guinea-pigs, dogs, 

 cais, lambs, and calves, although it must be borne in mind that its 

 virulence at any time is of low degree. Infection, either through natu- 

 ral or artificial channels, occi^rs only after considerable quantities of 

 infective material are swallowed. In man, the disease is progressively 

 marked by lassitude, loss of appetite, nausea, gastric pains, vomiting, 

 obstinate constipation, a fall in body temperature, odor of acetone 

 on the breath, the presence of acetone, diacetic, and /3-oxybutyric 

 acids, and the absence of dextrose in the urine. Large "doses of sodium 

 bicarbonate are relied on to effect a cure. In the herbivora, muscular ' 

 weakness, tremors, constipation, odor of acetone on the breath are 

 prominent features; in horses, profuse sweating may be a prominent 

 symptom. Degenerative and fatty changes of the parenchymatous 

 organs is the especial pathological featuremet with. 



Eradication of the disease in localities where it occurs may be 



