154 VARIOLA EQUINA — HORSE POX. 



have a distinct claim to be regarded as variolous, been held 

 to be a comparatively rare disease, even in the country where 

 its existence was first indicated more than half a century 

 ago. 



Believed originally by Jenner and his contemporaries to be 

 the source of vaccinia in the cow, it seems by experimentation 

 to be capable of transmitting that, both to the bovine species 

 and to man, either directly or indirectly ; and when so trans- 

 mitted, to be capable of protecting these from their variola, as 

 well as the human subject from vaccinia; while vaccination 

 protects the horse from its own variola. 



That the disease which by our German confreres has been 

 designated stomatitis pustulosa contagiosa, and by French 

 veterinarians stomatitis apJdheuse, or herpes phlyctenoide, and 

 by some of our English authorities regarded as true equine 

 variola — that this disease is frequently met with I am thoroughly 

 satisfied ; that it exhibits some of the characters of variolous 

 fever I am free to admit; Avhile additional resemblances to 

 variola, which have not been proved by me in actual practice, 

 seem powerfully supported by those upon whose ability and 

 judgment we may depend. Still there does not seem sufficient 

 evidence to compel us to regard it as true equine variola. 



The theory generally accepted regarding the accession of 

 variolous fever is, that a specific poison, proceeding from pre- 

 viously existing variola, is received into and affects the 

 economy ; that after a certain period of latency this originates 

 the primary fever, which lasts a few days, to be followed by 

 the secondary and diagnostic symptoms, the local disturbances 

 and lesions, the eruption on the skin and mucous membranes. 

 This eruption passes through certain stages of papule, vesicle, 

 and pustule. In the horse these local changes are chiefly 

 observed in the cutaneous surface of the inferior parts of the 

 extremities, particularly the hind ones, and on the mucous 

 membrane of the mouth, and skin immediately connected with 

 this membrane. When occurring on the extremities, the 

 eruption — partly from friction, and partly from soaking of the 

 epidermic scabs with the secretion — is extremely prone to 

 become confluent ; and the abundant discharge of purulent 

 material from an extensive surface has often caused this affec- 

 tion to be confounded with the skin disease known as ' grease.' 



