Text book of veterinary medicine, Volume 3 (of 5)

by James Law

The more severe forms are ushered in by violent trembling, or by stupor, apathy, and extreme muscular weakness, or actual paralysis. In such cases the animal may stagger or fall. Dysphagia or inability to swallow is often a marked symptom, the saliva falling in strings from the lips. Another common phenomenon is the rigid contraction of the muscles of the neck, back and loins, the parts becoming tender to the touch and a more or less prominent oposthotonos setting in. Twitching of the muscles of the shoulders and flanks may be noticed. Trismus also is sometimes seen. The breathing is usually rapid and catching and the temperature 104° to 106°. The pulse may be accelerated and hard, or weak and soft, or alternating. The eyes are violently congested, of a brownish or yellowish red color, and the eyeballs may be turned to one side. Paroxysms of delirium may set in, when the animal will push against the wall, or perform any of the disorderly movements described under meningo-encephalitis. Sooner or later coma and paralysis supervene, and death occurs in from five to forty-eight hours. In the most acute (fulminant) cases the animal falls and dies in convulsions. On an average the disease lasts from eight to fifteen days. In the more favorable cases, without any supervention of coma, recovery may begin on the third or fourth day.

Symptoms in the Ox. These are largely those of encephalo-meningitis. If they do not come on with the customary violence, there may be at first difficulty in prehension, mastication and swallowing of food; a rigid condition of the muscles of the neck, back, and sometimes of the jaws, and twitching of the muscles of the limbs, neck, lips, or eyes. For a time there may be hyperæsthesia, restlessness and irritability, stamping of the feet or shaking of the head, then there is liable to follow, dullness, apathy, stupor, coma and paralysis. As in the horse, the distinction from ordinary encephalo-meningitis will at times rest on the prevalence of the epizootic disease in the locality.

Symptoms in Sheep. The attack is described as coming on with weakness, dullness, lethargy, salivation, convulsions, oposthotonos, grinding of the teeth, succussions of the body and limbs, heat of the head, and stupor or paralysis unless death ensues during a paroxysm. The congestion of the head and of the encephalic mucous membranes, and the deviation of the eyes are constant features. Wischnikewitsch describes an extended outbreak in sheep in which the brain lesions were complicated by hepatization of the lungs, and bacilli were found in the various exudates. This reminds one of the presently accepted cause in man, which is, however, a micrococcus rather than a bacillus.

Symptoms in Dogs. These are described as some aberration of the senses, which gradually merges into stupor, coma and paralysis. While the animal is able to keep on his feet he sways and staggers, runs unconsciously against objects, or walks in a circle. There is heat of the head, injected eyes, sometimes drawn back or squinting, oposthotonos, and general spasms occurring in paroxysms. The duration of the disease is about the same as in the horse.

Differential Diagnosis. From other forms of meningitis this is easily distinguished. Fulminant cases almost all belong to this type, the fact of the coincident implication of brain and spinal cord is strongly suggestive of this form, and the occurrence of many cases at once, without any demonstrable toxic or thermic cause, is tolerably conclusive. From tetanus there is this added distinction, that the disease does not set in so slowly, the spasms of the neck and back are not so persistent, and stupor sets in early, in a way that is unknown in lockjaw. Rabies is recognized by the slow onset, the characteristic prodromata, the mischevious disposition, the depraved appetite, and by the history of its local prevalence. Tubercular meningitis in cattle has a similar association with tuberculous animals in the same family or herd, and often by the local indications of tubercle elsewhere, emaciation, unthriftiness, cough, flocculent and gritty nasal discharge, enlarged lymph glands, pharyngitis, mammary disease.

Treatment. With a disease so fatal prevention should be the first consideration and especially when it appears in an enzootic form. Even in the absence of a definite knowledge of its germ or toxin, it is logical to avoid the locality, condition, food or water by which such germ or toxin has presumably entered the system, together with every unhygienic condition, which may have reduced the resistance of the system and laid it open to the attack. The animals should be removed to a clean, airy, building and the old one should be thoroughly emptied, purified and whitewashed, the lime-wash containing 4 ozs. of chloride of lime, or 1 dr. of mercuric chloride to the gallon. Drains and gutters should have special attention and the animals should not be returned until the stable is thoroughly dry. A change of feed is imperative when there is any suggestion of damp, mustiness or fermentation, and even in the absence of such indications, since the ferments and their products may still be present in a dried condition. It should also be an object to correct any morbid or pyogenic condition of the pharynx, Eustachian pouch, nose or ear, by appropriate measures and the inhalation of sulphurous acid or chlorine may be resorted to with advantage.

As medicinal treatment Large advises to give at the outset 1 oz. aloes with one or two drs. of solid extract of belladonna and as an eliminant, derivative and nervous sedative there is much to be said for it. In case the difficulty of swallowing should prove a serious barrier a hypodermic injection of ½ dr. barium chloride, 1½ to 2 grs. eserine, or 2 grs. hydrochlorate of pilocarpin together with ¼ grain of atropin, may be employed. As a substitute for atropin, ergot, potassium bromide, chloral hydrate, chloroform, or phenacetin have been tried in different cases with varying results. Iodide of potassium has been employed with advantage in the advanced stages and in convalescence, and may be usefully employed in the early stages as a sedative to the nervous system, a deobstruant and an eliminant, if not as a direct antidote, to the toxins.

Bleeding is generally condemned, yet in acute cases where there are indications of active brain congestion, threatening convulsions or coma it may tend to ward off a fatal result.

Cold applications to the head are generally commended. Bags of ice or snow, irrigation with cold water, or cooling by running water at a low temperature, through a pipe coiled round the head or extended along the spine, will meet the purpose. Applied continuously this constringes the blood-vessels within the cranium as well as on its surface, lessens the exudation, and controls the pain and spasms. This may be advantageously associated with warm fomentations to the feet and limbs, friction, or even the application of stimulating embrocations to draw the blood to these parts. In the smaller animals even warm baths may be resorted to as a derivative, cold being meanwhile applied to the head and spine. This not only lessens the vascular pressure within the cranium, but secures elimination of toxic matters by both skin and kidneys. Cold pure water should be constantly within reach.

A most important thing in the horse is to put him in slings, if he is at all able to stand with their assistance. In decubitus he rests on his side, with the head on the ground, and lower than the splanchnic cavities. The result is a gravitation of blood toward the head. In the sling, with the head fairly raised the gravitation is the other way and the head is depleted. If the patient is too ill to be maintained in the sling, he may be packed up with bundles of straw on each side, so that his breast may lie on a thickly littered bed, and his head may be elevated.