A neutral principle obtained from several varieties of aloes, chiefly from Barbadoes and Socotrine Aloes.

Derivation.—Obtained by pulverizing and macerating aloes in cold water, and evaporating the resulting solution in vacuo. Aloin crystallizes out and is dried between folds of bibulous paper. It is purified by repeated solution in hot water, filtration, recrystallization, and finally by solution in hot alcohol and crystallization.

Properties.—A micro-crystalline powder or minute acicular crystals, lemon yellow or dark yellow in color, possessing a slight odor of aloes and intensely bitter taste. Soluble in water and alcohol.

Dose.—Horses and cattle, 2 to 3 dr.; sheep, 20 to 60 gr.; pigs, 10 to 40 gr.; dogs, 11 to 20 gr.; combined with other purgatives.

PREPARATIONS

TINCTURA ALOES ET MYRRHAE—TINCTURE OF ALOES AND MYRRH

Made by maceration and percolation of purified aloes, 100 parts; myrrh, 100 parts, and liquorice root, with alcohol and water to make 1000.

Dose.—Dogs, ¹/₂ to 1 dr.

Action.—Aloes is a purgative, acting chiefly on the large intestines; small doses are bitter tonics; it stimulates both peristalsis and secretion, increases secretion of bile; is also diuretic; applied externally it is stimulant and desiccant; the Barbadoes is the most active and uniform in its effects.

Aloes should be kept in lumps in tin cans or other good containers, only powdered for immediate use; in melting aloes don’t let the temperature rise above 120 degrees as it impairs the activity by converting the active aloin into inert resin. Aloes operate in from 12 to 24 hours after administration; don’t repeat an aloetic purge until 24 hours have elapsed. It also does not cause catharsis. In about 15 hours, the patient should be exercised, but returned to the stall as soon as the desired effect is evident. If it fails to act in 24 hours, linseed oil may be given. Aloin appears to contain the active principles of aloes, and is usually as operative, but some manufactures are ineffective.

Uses Internal.—In dyspepsia with capricious appetite, irregularity of the bowels, hide-bound horses, worms; is used in colic, both spasmodic and flatulent, for overloaded condition of the bowels; to promote excretion of waste products from the bowels and the blood, and consequently relieve febrile symptoms; rheumatic attacks, skin irritation, swollen limbs and inflamed joints; in lymphangitis to prevent and aid in curing. By attracting the blood to the bowels, it is useful in congestion or inflammation of the brain and spinal cord, full doses being necessary; in paralysis, paraplegia or hemiplegia or reflexed paralysis due to indigestion, give full doses. Aloes should not be used in irritation or inflammation of the alimentary canal or piles. It is not advisable to give an aloetic purge when the temperature is above 102° F. Nor in hemorrhage from the rectum; in high fevers it is apt to cause superpurgation, also should not be used where there is great debility or weakness. In influenza the bowels are apt to be irritable and oil is preferable to aloes. Don’t use during pregnancy; may cause abortion. For young foals or other animals, the gentler purgative, such as linseed or castor oil should be used. The medical value of aloes being large, it is impossible to enumerate all the diseases in which it is useful. Externally the tincture of aloes and myrrh is sometimes applied as a stimulant to wounds, and powdered aloes is mixed with plaster of paris in making splints for dogs to prevent these animals from biting and tearing them off. Internally aloes should be combined with ginger, nux vomica and given in capsule or bolus.