QUARTER-EVIL 143 



extent. The swelling may assume a dark colour, and crackles on 

 being touched. There is high temperature, and secondary motor and 

 functional disturbances. The disease ends fatally in two or three 

 days. 



Slight injuries to the surface of the skin or mucous membrane 

 are sufficient for the introduction of the 

 causal bacillus. This organism is, like the 

 bacillus of tetanus, an anaerobe, existing in 



the superficial layers of the soil. From its . ' i ^ A ^ I 

 habitat it readily gains entrance to animal 



tissues. It has spores, but though they ' ^ ' ' V 



are of greater diameter than the bacillus J Q I \ \ 



itself, they are not absolutely terminal. 

 Hence they merely swell out the cap- 

 sule of the bacillus, and produce a club- 

 shaped rod. The bacillus forms gas while 

 growing in the tissues and in artificial cul- „ „„ „. «„ .„ 



° °T-, J 11-1 T • 1 Fig. 20.— Diagram of Bacillus 



ture. Jlixternal physical conditions have of symptomatic Anthrax. 



little effect upon this organism, and dried 



and even buried flesh retains infection for a long period of 



time. 



Quarter-IU, Quarter-Bvll, or Black-Iieg 



Quarter-ill may be said to lack much of the importance and interest which is 

 attached to anthrax, inasmuch as it is confined to two domestic animals — sheep and 

 cattle — and is not communicable to man. It, however, resembles anthrax, in so 

 far as they are both caused by the introduction into the blood of the healthy 

 animal of specific bacilli. Both diseases have a tendency to recur on farms or 

 premises on, or in, which animals aifected with these diseases have been previously 

 kept. On the other hand neither anthrax nor quarter-ill is communicable by 

 association of the affected with the healthy animal, and in that respect they differ 

 from most of the contagious diseases which are legislated for in this country. 

 Another peculiar feature of quarter-ill is that while it is very fatal to sheep at any 

 age, cattle over two years may be said to have an immunity against the disease. 



The symptoms of quarter-Hi in young cattle are so strikingly different from any 

 other disease that an error in diagnosis is almost impossible. The first indication of 

 an animal being affected with quarter-ill is a marked stiffness or lameness of one of 

 the limbs ; it is exceedingly duU, and presents a most anxious and dejected 

 appearance, does not feed, and it is with extreme difficulty that it can be forced to 

 move. Very soon after the limb is attacked a swelling appears beneath the skin, 

 usually upon one of the hind quarters, which is extremely hot, increases in size 

 rapidly, and is most painful to the animal when touched. This swelling has a 

 disposition to extend down the leg, or perhaps along the loins and back, and when 

 pressed gives a peculiar crackling sensation to the fingers. In almost every instance 

 death supervenes within a few hours after the swelling has appeared. 



In the case of sheep the symptoms are not of so marked a character. The first 

 indication is lameness, but 'the swelling is not so observable in sheep as in cattle, 

 being hidden to a great extent in the case of the former by the fleece. 



There is no doubt that the disease exists to a greater extent among the sheep in 

 certain counties in England than has been generally known, and from the rapidity 

 with which sheep frequently die it is often locally called " strike." 



Should any doubt exist as to whether a sheep has died from quarter-ill, the 

 difficulty can easily be solved by making an incision through the skin of the dead 



