258 DISEASES OF CATTLE. 



A marked characteristic of this form of illness is that it attacks 

 almost every calf born in the herd, or in the building, rather, and if 

 the calf escapes an attack in the first two or three days of its life it 

 usually survives. Those that recover from an attack, however, are 

 liable to suffer from an infective inflammation of the lungs one or two 

 weeks later. The infection clings to a stable for years, rendering it 

 impossible in many cases to preserve and raise the calves. It has 

 frequently coincided with abortions and failures to conceive in the 

 same herd, so that it has been thought that the same infective germ 

 produces one type of abortion. On the other hand, the removal of 

 the calving cow from the herd to calve in a separate building, hitherto 

 unused and therefore uninfected, usually secures the escape and sur- 

 vival of the offspring. 



The disease has been traced by Nocard and Lignieres to a small 

 bacillus having the general characters of those which produce hemor- 

 rhagic septicemia, which is usually combined with a variety of others, 

 but is in some cases alone and in pure culture, especially in the 

 joints. The theory of Lignieres is that this bacillus is the primary 

 offender, and that once introduced it so depresses the vital powers of 

 the system and tissue cells that the healthy resistance to other bac- 

 teria is impaired or suspended, and hence the general and deadly 

 invasion of the latter. 



Inoculations with this bacillus killed guinea pigs or rabbits in six 

 to eighteen hours, and calves in thirty hours, with symptoms and 

 lesions of hemorrhagic septicemia, including profuse fetid diarrhea. 



The predominance of the early and deadly lesions in the alimen- 

 tary tract would seem to imply infection through the food, and the 

 promptitude of the attack after birth, together with the frequent coin- 

 cidence of contagious abortion in the herd, suggest the presence of 

 the germ in the cow; yet the escape of the calf when the cow calves 

 in a fresh building is equally suggestive of the infection through 

 germs laid up in the building. This conclusion is further sustained 

 by the observation that the bacillus evidently enters by the raw, 

 unhealed navel, that it is diffused in the blood, and that a very care- 

 ful preservation of the navel against infection gives immunity from 

 attack. 



Prevention.— The disease is so certainly and speedily fatal that it is 

 hopeless to expect recovery, and therefore prevention is the rational 

 resort. 



When a herd is small, the removal of the dam to a clean, unused 

 stable a few days before calving and her retention there for a week 

 usually succeeds. But it is in the large herd that the disease is mainly 

 to be dreaded, and in this it is impossible to furnish new and pure 

 stables for each successive group of two or three calving cows. The 

 thorough disinfection of the general stable ought to succeed; yet I 



