916 ECZEMATOUS DERMATITIS. 



Griinwald describes an enzootic dermatitis which appeared during 

 the hottest part of summer amongst horses stalled in open sheds, and 

 in which the lower portions of the limbs were continually exposed 

 to the sun's rays. Horses sheltered from the sun were not affected, 

 a fact which led Griinwald to compare the condition with erythema 

 solare of man. 



Kropfl noticed the same thing in horses at grass. Only the 

 unpigmented portions of skin in the hind limbs seemed to be diseased. 



Bermbach believed that mud-fever was conveyed from horse 

 to horse by using the same washing-pails, &c. More probably the 

 same general external influences were at work. 



Amongst chemical irritants must be numbered chalk-dust. In 

 the army its action is often troublesome, on account of horses becoming 

 affected immediately they are brought into chalky regions. The 

 action is chemical, as shown by the fact that disease is favoured by 

 washing the legs, the best preventive being simply to cleanse the 

 parts with a dry cloth. 



Course. Early and appropriate treatment generally results in 

 complete cure in eight to fourteen days. When, however, the disease 

 is neglected, recovery is impeded by the formation of fissures and 

 of new connective tissue, which latter sometimes produces prominent 

 thick swellings in the pastern. Though simple cracks soon heal with 

 rest and proper treatment, large masses of new tissue are very often 

 difficult to deal with. Before giving an opinion, the parts should 

 therefore be thoroughly examined. 



The treatment of eczematous dermatitis requires in the first 

 place rest, because movement keeps up inflammation and favours 

 the formation of fissures and of excessive quantities of cicatricial 

 tissue. The skin should be carefully cleansed with warm water 

 and a neutral soap, the swellings rinsed with an antiseptic solution, 

 dried, and dressed with iodoform and tannin (1 — 3). After the 

 preliminary washing and disinfection, it is very important to avoid 

 again wetting the parts. This is one of the chief secrets in the 

 successful treatment of these forms of dermatitis. Astringent dusting 

 powders are generally useful. Pyoktanin has been highly recom- 

 mended, but its powerful staining properties render it unpopular. 

 Thioform, dermatol, glutol, and amyloform (all compounds of formic 

 acid with neutral bases) are easy to use and efficacious. An 

 ointment of red oxide of mercury one part, with paraffin base or 

 lanolin ten parts, is useful. It may be smeared on wadding, laid on 

 the surface of the wound, and fixed in position by a bandage. This 

 dressing may be left in position until wet through, when the diseased 



