160 VARIOLA EQUINA — HORSE POX. 



From ' grease,' ' steatorrlicea/ and ' eczema impetiginodes ' — 

 Avith which in their severer forms horse-pox has much in 

 common — it may be distinguished by carefully observing, 

 first, the nature of its attack; second, the character of its 

 pustulation ; and third, its course and termination. In its 

 attack horse-pox is sudden, usually accompanied with a certain 

 amount of fever, and the local inflammation and phenomena 

 are subsequent to, or coincident with, the pyrexia. In grease 

 the attack is gradual : we are probably not aware of its ex- 

 istence until it has made so much progress that the local 

 lesions are evidently acting in the production of systemic dis- 

 turbance, which thus as a rule follows, and does not precede, 

 the local changes. 



When the pustules of variola are discrete on the skin of the 

 heels and lower parts of the extremities, they are not difficult 

 to diagnose ; and when they have become confluent, and the 

 scabs are matted together, and remain partially floated, as it 

 were, over a considerable raw surface, on their removal by 

 washing with soap and water, the same characteristic features 

 of the sore will be revealed which mark the isolated pustules. 

 It is circular, comparatively shallow, with occasionally nume- 

 rous hairs projecting from it, indicating the non-destruction of 

 the deeper layers ; or where suppuration has been longer con- 

 tinued and more severe, loops or projections of granulation- 

 tissue will be prominently displayed. 



Most frequently at the full development of the eruption all 

 the affected surface is covered with a firm brown crust, partially 

 adherent, chiefly by means of the hairs which project through 

 it: this crust, or at least a crust so distinct and of this 

 character, does not exist in specific grease. The character of 

 the course of the eruption, which in reaUty is the essential of 

 the disease in equine variola, is benign, proceeding through a 

 short and ascertained course to perfect restoration to health ; 

 in grease the local lesions are not disposed to heal, and they 

 do not pass through definite and understood phases, and are 

 sometimes difficult to control. 



Treatment. — Belonging to the class of eruptive fevers which 

 naturally tend to restoration to health, after passing through 

 an ascertained and definite course, interference with this is 

 likely to be productive of undesirable results. Our object 



