Impetigo. Dermatitis Lichenoides. Acne. 



887 



fectious (Impetigo contagiosa) and is accompanied by acute swelline 

 of the neighboring lymph glands ; it always runs a favorable course 



According to Burke the disease develops in horses with fine skin 

 under the influence of irritating agencies and unfavorable hygienic con- 

 ditions. The resultant pustules are superficial, at first white like mother- 

 of-pearl, later purulent, then rupture quickly, and their contents 

 dry up into yellow crusts ; when these fall off a hairless spot remains 

 which heals without scaling. In contrast to eczema the exanthema runs 

 a rapid course and heals quickly ; there is no itching and transmission 

 to other animals is easy (Vet. Journ. 1890, 77). 



According to Benion a similar disease develops in young swine in 

 the neighl)orhood of the eyes, more rarely on other parts of the body 

 with the formation of small pustules, in the place of which soft crusts 

 arise later on. The process is accompanied by a catarrh of the con- 

 junctivae, nose and mouth, and heals within 2 to 3 weeks (Diet., 1888, 

 A.vl, 268). 



Schindelka several times saw an eruption in old nursing or pregnant 

 bitches which occurred independently of distemper. 



As a secondary affection impetigo develops in the course of dis- 

 temper, strangles, swine plague and hog cholera as well as in rinder- 

 pest. 



The treatment consists in softening of the scabs or washing with 

 creolm or soap solution and subsequent dressing with a disinfecting or 

 astringent ointment. 



Dermatitis Lichenoides. By this name Dages described a disease of the 

 horse m the course of which large, dry, bald, non-itchiug surfaces formed on the 

 root of the tail, ou the back, neck and thighs. After the lapse of six months the 

 skm on these spots became painful, inflamed and infiltrated, and ha2elnut-sized 

 nodules developed on it; at the same time there was violent itching. Later on 

 the nodules liegan to bleed, and thick, yellowish crusts formed, underneath which 

 the skm was covered with pus. Finally the nodules became smaller, and in their 

 places pea-sized elevations remained, on the surfaces of which the epidermis was 

 thick and rough. The acute attack lasted a month, it recurred annually in winter, 

 and the affection finally became so extensive that the horse had to be killed at 

 the end of three years. Neither in the epidermis, nor the crusts or in the pus 

 could vegetable or animal parasites be demonstrated, and transmission experi- 

 ments on guinea pigs were unsuccessful. (Dagos, Bull., 1894, 442.) 



14. Acne. 



{Heat rash, summer rash, summer scab, sweating eczema of the 



saddle region, saddle scab, heat nodides, heat pox, nodular 



or tubercle rash in horses; Acne simplex s. vidgaris; 



Boutons [French]; Akne [German].) 



By acne one understands an inflammation of the sebaceous 

 glands and hair follicles, not infrequently passing on to pus for- 

 mation, and characterized by pin-point to bean-sized nodules 

 appearing in the otherwise healthy skin. 



According to Schindelka the skin diseases mentioned in the title 

 are considered as acne since they do not exhibit the characteristics of 

 eczema with which most authors have classified them (socalled papulo- 

 vesicular eczema). 



Etiology. In certain cases acne probably results from an 

 infection with pus bacteria (Frick) wliicli evidently enter 



