DISEASES OF HORSES 301 



BOILS, OR FURUNCLES. 



These may appear on any part of the skin, but are especially 

 common on the lower carts of the limbs, and on the shoulders and 

 back where the skin is irritated by accumulated secretion and chaf- 

 ing with the harness. In other cases the cause is constitutional, or 

 attended by unwholesome diet and overwork with loss of general 

 health and condition. They also follow on weakening diseases, not- 

 ably strangles in which irritants are retained in the system from 

 overproduction of poisons and effete matters during fever, and im- 

 perfect elimination. There is also the presence of a pyogenic bac- 

 terium, by which the disease may be maintained and propagated. 



While boils are pus-producing, they differ from simple pus- 

 tule in affecting the deepest layers of the true skin, and even the 

 superficial layers of the connective tissues beneath, and in the death 

 and sloughing out of the central part of the inflamed mass (core). 

 The depth of the hard, indurated, painful swelling, and the forma- 

 tion of this central mass or core, which is bathed in pus and slowly 

 separated from surrounding parts, serve to distinguish the boil alike 

 from the pustule, from the farcy bud, and from a superficial abscess. 



Treatment. To treat very painful boils a free incision with a 

 lancet in two directions, followed by a dressing with one-half an 

 ounce carbolic acid in a pint of water, bound on with cotton wool 

 or lint, may cut them short. The more common course is to apply 

 a warm poultice of linseed meal or wheat bran, and renew daily 

 until the center of the boil softens, when it should be lanced and 

 the core pressed out. 



If the boil is smeared with a blistering ointment of Spanish 

 flies and a poultice put over it, the formation of matter and separa- 

 tion of the core is often hastened. A mixture of sugar and soap laid 

 on the boil is equally good. Cleanliness of the skin and the avoid- 

 ance of all causes of irritation are important items, and a teaspoon- 

 ful of bicarbonate of soda once or twice a day will sometimes assist 

 in warding off a new crop. 



NETTLERASH ( SURFEIT, OR URTICARIA). 



This is an eruption in the form of cutaneous nodules, in size 

 from a hazelnut to a hickory nut, transient, with little disposition 

 to the formation of either blister or pustule, and usually connected 

 with shedding of the coat, sudden changes of weather, and un- 

 wholesomeness or sudden change in the food. It is most frequent 

 in the spring and in young and vigorous animals (good feeders). 

 The swelling embraces the entire thickness of the skin and ter- 

 minates by an abrupt margin in place of shading off into surround- 

 ing parts. When the individual swellings run together there are 

 formed extensive patches of thickened integument. These may ap- 

 pear on any part of the body, and may be general ; the eyelids may 

 be closed, the lips rendered immovable, or the nostrils so thickened 

 that breathing becomes difficult and snuffling. It may be attended 

 by constipation or diarrhea or by colicky pains. The eruption is 

 sudden, the whole skin being sometimes covered in a few hours, 



