CONTAGIOUS PUSTULOUS DERMATITIS 267 



Horses. — The favorite seat of herpes in the horse is the 

 head, back, shoulders, and croup. As a rule it assumes the 

 form of round, well-defined bald spots the size of a 25-cent 

 piece. Usually there is no pruritus. In rare instances a 

 Herpes vesiculosus occurs on the sheath and inner surface of 

 the hind limbs, with the formation of scabs and crusts. 



Treatment. — The treatment depends somewhat on the ex- 

 tent and form of the eruption. When feasible it is advisable 

 to shear off the hair and soften up the crusts with green soap. 

 This may be followed by painting the areas with tincture of 

 iodin or salicylic acid in alcohol (1 to 10). In horses mercuric 

 ointment is useful. In obstinate cases nitric acid may be 

 tried. However, most cases yield to treatment with any 

 disinfectant. One attack of herpes produces a certain im- 

 munity against subsequent ones. 



FAVUS. 



Favus is a contagious skin disease common in man but 

 very rare in animals, caused by a fungus similar to the Tricho- 

 phyton tonsurans and called the Achorion Schoenleinii. It 

 forms round, thick scabs on the skin which being depressed 

 in their centres are saucer- or shield-shaped. The scabs have 

 a sulphur-yellow color, especially toward the centre. They 

 appear upon the head, abdomen, and feet of carnivora. In 

 fowls the comb and wattles are the favorite seats. The treat- 

 ment is the same as for herpes. 



CONTAGIOUS PUSTULOUS DERMATITIS. CONTAGIOUS 



ACNE. 



Definition. — Contagious pustulous dermatitis is a benign 

 pustular exanthema of horses which occurs in the regions of 

 the harness and saddle rests. 



Etiology. — The disease is not very common, but occurs 

 occasionally enzootically. The pustules are caused by the 

 acne bacillus. Infection takes place usually through inter- 

 mediary agents such as harness and saddles. 



Symptoms. — In the region noted round or oval , swellings 

 the size of a 25-cent piece appear, which in a day or so 



Digitized by Microsoft® 



