FOOT ROT IN SHEEP.
—A chronic inflammation of the foot, marked by ulceration, softening of the hoof, lameness, and the discharge of a sticky material which has a very fetid odor. It is a contagious disease, and is produced by a germ that lives in the soil and gains entrance to the feet through wounds and surfaces chafed by barbed grasses and stones, or by gritty clay, which becomes lodged between the toes and hardens there.
The first symptom is a slight lameness. If the affected foot be examined, that part just above the horny part of the cleft of the foot, either in front or behind, will be found inflamed, feverish, and moist. Erosions or ulcers soon appear, generally on the heel. These penetrate the foot and burrow beneath the horny parts, causing fistulous tracts from which exudes a foul-smelling pus possessing an odor sufficiently characteristic to indicate the disease in a flock, even without a close examination. In time, the foot becomes greatly overgrown and deformed, the hoofs increasing in length and curling upward. In bad cases, the suffering is so great the animal lies down most of the time, but when only the front feet are diseased, it will crawl around on its knees.
That the disease is contagious is shown by the fact that it generally starts in one foot and spreads to the others, and, at the same time, the feet of other sheep in the same flock become diseased in the same way, the outbreak covering a period of several months. In cases that recover spontaneously the foot is deformed and the joint is stiffened. It is only in virulent outbreaks where all the feet are diseased, or where some complication, such as maggots, is present, that deaths occur.
Having as its cause a microbe, it is proper to take measures of prevention as well as cure. In purchasing sheep, it is highly advisable to keep them isolated for a week, as a test. All overgrown hoofs should be trimmed. Sores or wounds, from any cause, should be carefully disinfected daily. Low, boggy lands should not be used as pasture for sheep, and dirty, unsanitary pens should be made sanitary, as these all predispose to an outbreak of the disease.
As treatment, first isolate all affected animals. Mild cases are best treated by making the sheep stand for several minutes daily in a trough containing a disinfectant, or, better still, by arranging the trough of suitable length with fenced-up sides and a widened entrance, so the sheep can be easily started into the inclosure and made to wade through the disinfectant.
In bad cases and where the hoof is underrun with pus, the horn and all overgrowths must be cut away so as to expose the diseased parts to the action of the disinfectant. The foot should then be dried, dusted with finely powdered burnt alum, and bandaged to keep out the dirt. This antiseptic treatment of the feet must be kept up daily as long as the disease exists. Any of the following may be used: 1 pound chloride of lime to 12 quarts of water; 1 pound of pure carbolic acid to 4 gallons of water; a solution of creolin; a coal-tar disinfectant of the same strength; or any good sheep dip containing these substances in the proper amounts.