DISEASES OF THE HORSE. 435 



when it becomes ag-grtiva-ted it ma}' merge in part or in whole into a 

 papular, vesicular, or pustular eruption. 



Erj'tbema may arise from a variet}' of causes, and is often named in 

 accordance with its most prominent cause. Thus the chilling, or par- 

 tial freezing, of a part will give rise to a severe reaction and conges- 

 tion. Where snowy or ic}^ streets have been salted this may extend 

 to severe inflammation with vesicles, pustules, or even sloughs of 

 circumscribed portions of the skin of the pastern (chillblain, frost- 

 bite). Heat and burning have a similar effect, and this often comes 

 from exposure to the direct rays of the sun. The skin that does not 

 perspire is the most subject, and lience the white face or wJilte liml) 

 of a horse becoming dried by the intensity of the sun's rays often 

 suffers to the exclusion of the rest of the body {white face and foot 

 disease). The febrile state of the general system is also a potent 

 cause, hence the white-skinned horse is rendered the more liable if 

 kept on a heating ration of buckwheat, or even of wheat or maize. 

 Contact of the skin with oil of turpentine or other essential oils, with 

 irritant liquids, vegetable or mineral, with rancid fats, with the acrid 

 secretions of certain animals, like the irritated toad, with pus, sweat, 

 tears, urine, or liquid feces, will produce congestion or even inflam- 

 mation. Chafing is a common cause, and is especially liable to affect 

 the fat horse between the thighs, by the side of the sheath or scrotum, 

 on the inner side of the elbow, or where the harness chafes on the 

 poll, shoulder, back, breastbone, and under the tail. The accumula- 

 tion of sweat and dust between the folds of the skin and on the sur- 

 face of the harness, and the specially acrid character of the sweat in 

 certain horses contribute to chafing or '' intertrigo.'- The heels often 

 become congested, owing to the irritation caused b}' the short bristly 

 hairs in clipped heels. Again, congestion maj' occur from friction b}' 

 halter, harness, or other foreign bodj' under the pastern, or inside the 

 thigh or arm, or by reason of blows from another foot (cutting, inter- 

 fering, overreach). Finally, erj^thema is especially liable to occur in 

 spring when the coat is being shed, and the hair follicles and general 

 surface are exposed and irritable in connection with the dropping of 

 the hairs. 



If due onh' to a local irritant, congestion will usually disappear when 

 such cause has been removed, but when the feeding or S3\stem is at 

 fault these conditions must be first corrected. While the coat is 

 being shed the susceptibility will continue, and the aim should be to 

 prevent the disease developing and advancing so as to weaken the 

 skin, render the susceptibility permanent, and lay the foundation of 

 persistent or frequently recurring skin disease. Hence at such times 

 the diet should be nonstimulating; anj'' excess of grain and above all 

 of buckwheat, Indian corn, or wheat being- avoided. A large grain 



