BLISTERING. The operation of stimulating the surface of some part of the body of an animal, by means of acrid applications, so as to raise small vesicles at the surface. It is frequently employed for the purpose of removing local affections of different kinds, such as hard, indolent tumors. The ordinary horse-doctor resorts to• blistering whenever he suspects internal inflam mation. It is as disreputable as it is vicious, since in deep-seated inflammations, it causes pain and irritation of the viscera, and also leaves a blemish often difficult to eradicate. The use of blisters is, after acute inflammation has ceased, to absorb deposits, or effect some organic change by stimulation, as in reducing, for instance, an enlarged gland, the ripening (suppuration) of an abscess, hastened, etc. A strong blistering oint ment is made of one ounce each of powdered resin and powdered cantharides (blistering fly), and four ounces of lard; place the lard and resin in a vessel and set in boiling water until heated; then add the flies and stir until cool. Blistering ointment of medium strength may be made of one ounce powdered cantharides and six ounces of lard, treated as before directed. A mild oint ment that will not blemish, but thoroughly applied will raise a good blister is made with one ounce of powdered cantharides and twelve ounces of lard, made as before directed. Avoid the addition of arsenic, corrosive sublimate, and other poisons; they are useless and dangerous. Blistering ointments are applied by first shaving off the hair, washing and drying the skin, and rubbing the ointment in with considerable fric tion. If first brushed over lightly with turpen tine it will act quicker, but this is not to be used in ordinary cases. If it be required that the blister shall act for a considerable time, dress the part with the blistering ointment diluted with oil from one-half to one-quarter the original strength. If
this is not necessary, foment the blistered part with warm water the second day, and dress the part with lard or olive oil. When any animal is• blemished it must be so secured that it can not bite or rub the irritated part. A tincture or sweating lotion that will not raise a full blister, but simply irritate the part, is made by steeping for ten or fifteen days, in a warm place, one ounce of best powdered cantharides in a pint of proof" alcohol. This strength may be increased if neces sary by adding from one to four ounces of solution of ammonia to a preparation containing one ounce of cantharides. This sweating blister may be ap plied repeatedly and without shaving the hair. A very strong blistering solution may be made by adding a quart of spirit of turpentine to four ounces of powdered cantharides, and macerating the whole for a month, when the clear fluid will form a very strong liquid blister. If so powerful a stimulant be not required, the liquid may be diluted with an equal part of oil. As a rule cattle are not blistered. A mustard plaster made with hot water and well rubbed in is usually all that will be needed to produce the necessary irritation. In blistering always remember the following rules : Avoid much blistering in hot weather. Never blister more than two places at one time; or an inflamed part, or when erysipelas or mortification is suspected. Blistering is apt to produce stranguary in horses, if not watched. In case of nervous irritability, loss of appetite, or stranguary (inability to urinate), following blis tering, give the horse two drachms of opium; wash the blistered part with strong suds of warm water and soft soap; dry, and dress with sweet oil. Instead of opium, five to ten grains of mor phia may be used, or inject hypodermically one or two grains of morphia under the skin.