CEAPTER XV. 



CONTAGIOUS DISEASES. 

 CATTLE PLAGUE. 



Synonyms. — Pdndcrpcst (G.) ; Typhus bourn contayiosus'^ (L.) ; 

 Fievre pcstilentielle du gros hetail (F.) 



Definition. — A specific, malignant, and contagious fever, said 

 by Semner to be due to a streptococcus v»'hich liquefies gelatine, 

 and which induced the disease in a calf inoculated with the 

 cultivation. The calf died in seven days. The cocci were 

 said to lose their virulence by successive cultivation, and a pro- 

 tective vaccine was thus obtained. Other observers have 

 described them as spore-bearing bacilli, transformed into micro- 

 cocci, isolated or in chains, and as a short bacillus with 

 rounded ends, which may also present the appearance of a 

 micrococcus or leptothrix. Inoculations with cultures induced 

 the disease. It is indigenous to the Asiatic steppes of 

 Russia, also Hindostan, Persia, China, Burmah, Cochin-China, 

 Thibet, Ceylon, &c., never occurring in this country but as the 

 result of direct or indirect communication between imported 

 cattle (which have been exposed to the contagium) and those of 

 our own shores. It is unknown in America and Australia. 

 The disease has a period of incubation varying from four 

 to eight days, at the end of which time its local manifestations 

 are generally developed. It runs a definite course, and usually 

 terminates fatally ; but where recovery takes place the animal 

 is rendered unsusceptible to another attack. 



It is essentially a disease of the bovine family (the ox, auroch, 

 and zebu), but it may be communicated to the sheep, goat, deer, 

 camel, giraffe, antelope, gazelle, and even the peccary. 



^ The word contagiosus was introduced into medicine by Vegetius, and is now 

 recognised as a generic term. 



