Читать книгу Special Report on Diseases of Cattle - Lowe - Страница 146

Inflammation of the brain is technically termed encephalitis and of its membranes cerebral-meningitis, but as both conditions usually occur together, and since it is practically impossible to distinguish one from the other by the symptoms shown by the diseased animal, they may as well be considered together here as varieties of the same disease. Staggers, coma, frenzy, etc., are terms that are sometimes applied to this disease in its different forms or stages.

Causes.—Severe blows on the head with a hard object, or the head coming violently in contact with the ground or other hard substance in a fall, may be followed by encephalitis. Irritation caused by tumors in the brain may produce inflammation. Feed containing deleterious matters—for example, ergot (see Pl. V) and other fungi which contain a narcotic principle—is the most frequent cause of this affection, and hence it is often called "grass staggers" and "stomach staggers." Highly nitrogenous feeds are blamed for causing this disease. Parasites, mineral and narcotic poisons, hot weather, and severe exertion or excessive excitement may cause this condition. Inflammation of the brain may occur as a complication of some infectious disease or may follow some forms of indigestion. In many localities certain plants have the reputation of causing staggers.

Symptoms.—The symptoms vary much, but a careful observer will detect a trouble connected with the nervous system without much uncertainty. The first signs may be those of frenzy, but generally at the start the animal is dull and sleepy, with little or no inclination to move about; the head may be pressed against the wall or fence and the legs kept moving, as if the animal were endeavoring to walk through the obstruction; the body, especially the hind part, may be leaned against the side of the stall or stable, as if for support. The bowels are constipated; the urine, when passed, is small in quantity and darker in color than natural. There may be trembling and even spasms of muscles in different parts. In the dull stage the animal may breathe less frequently than is natural, and each breath may be accompanied with a snoring-like sound. The pulse may be large and less frequent than normal. If suddenly aroused from the drowsy state, the animal appears startled and stares wildly. When moving about it may stagger, the hind quarters swaying from side to side.

If delirium ensues, the cow is commonly said to be mad. She may bellow, stamp her feet, run about wildly, grate the teeth, froth at the mouth. If she is confined in the stable, she rears and plunges; the convulsions are so violent in many instances that it is really dangerous for one to attempt to render aid. The body may be covered with perspiration. She may fall; the muscles twitch and jerk; often the head is raised and then dashed against the ground until blood issues from the nose and mouth; the eyes may be bloodshot and sightless; the limbs stiff and outstretched, or they may be kicked about recklessly; the head may be drawn back and the tail drawn up; the urine may be squirted out in spurts; often the "washer" (membrane nictitans) is forced over the eye. When the convulsions cease they may be followed by a period of quiet unconsciousness (coma) which is more or less prolonged, when the animal may gradually regain consciousness, get up on its feet, and perhaps quietly partake of food, if there be any within reach, while at other times it arises with much difficulty and staggers blindly about the stall or field.

It must be remembered that all the foregoing symptoms are not always seen in the same case. In those cases usually designated "sleepy staggers" the general symptoms of drowsiness are presented, while in other cases the symptoms of frenzy cause the affection to be called "mad staggers." In other cases there are symptoms of paralysis, swaying of the hind quarters, inability to rise, etc., and sometimes these symptoms of paralysis are the most striking manifestations and continue until death. Acute cases are accompanied by fever.

It is well to remark that when the disease follows injuries to the head the symptoms may not be manifested until two or three days (or longer) after the accident.

Treatment.—Recoveries are rare in spite of careful attention. To be of any service whatever the treatment must be prompt and begin with the disease. In the early stage, when the pulse is large, most cases will admit of bleeding. Eight or 9 quarts of blood should be taken from the jugular vein. This should be followed immediately by a purgative, the following for a cow of average size: Epsom salt, 24 ounces; pulverized gamboge, one-half ounce; croton oil, 20 drops; warm water, 3 quarts; mix all together and give at once as a drench. About 2 quarts of warm water or warm soapsuds should be injected with a syringe into the rectum every three or four hours. It is best to keep the animal in a quiet, sheltered place, where it will be free from noise or other cause of excitement. All the cold water the animal will drink should be allowed, but feed must be withheld, except bran slops occasionally in small quantities, or grass, if in season, which may be cut and carried fresh to the patient.

The skull must be examined, and if sign of injury is found, appropriate surgical treatment should be given.

During the convulsions all possible efforts should be made to prevent the animal injuring itself. The head should be held down on the ground and straw kept under it. Cold water may be continuously poured on the head, or bags filled with ice broken in small pieces may be applied to the head. Different authors recommend different remedies to allay the convulsions, but for two reasons it will be found extremely difficult to administer medicines during the convulsions: (1) While the animal is unconscious the power to swallow is lost, and therefore the medicine is more liable to go down the windpipe to the lungs than it is to go to the paunch; (2) the convulsions are often so violent that it would be utterly useless to attempt to drench the animal; and furthermore it must be borne in mind that during this stage the functions of digestion and absorption are suspended, and as a consequence the medicine (provided it finds its way to the paunch) is likely to remain there unabsorbed and therefore useless.

A blistering compound, composed of mustard, 1 ounce; pulverized cantharides, one-half ounce; hot water, 4 ounces, well mixed together, may be rubbed in over the loins, along the spine, and back of the head on each side of the neck. This is occasionally attended with beneficial effect, and especially so in those cases when paralysis is present.

If the purgative acts and the animal shows signs of improvement in the course of two or three days, 2 drams of iodid of potassium may be given every night and morning, dissolved in a half bucketful of drinking water, if the animal will drink it, or it may be dissolved in a half pint of water and given as a drench. Great care must be observed in regard to the food, which should be nutritive, but not coarse, and at first in small quantities, gradually increased as the patient improves. After some progress is made toward recovery 1½ drams of pulverized nux vomica may be given twice a day, added to the iodid of potassium drench. This should be administered so long as a staggering gait continues.

In those rare cases when recovery takes place it is only partial as a rule, as there is generally a sequel which remains, such as partial paralysis. However, this is but a slight drawback in cattle, because when it is seen to persist the medicine should be stopped and the animal fattened for butchering.

Post-mortem examinations discover congestion of the brain and its membranes. In those cases which have exhibited much paralysis of the hind legs before death the cord may be congested in the lumbar region (loins). When the disease has been caused by injury to the head, the congestion and extravasated blood may be found inside of the cavity in the location corresponding to the place where the injury was inflicted externally. In some cases pus is also discovered. It remains to be said that in all animals that have died from this affection the lungs are found very much congested. This may lead the superficial observer to suppose that the disease was a lung affection, but in fact it is only a natural consequence when death ensues from brain disease.