Symptoms in Sheep. The sheep is often drowsy, dull and stupid, lying by itself with head low or laid backward. During the periods of excitement it works the jaws, froths at the mouth, carries the head turned in one direction, upward or lateral, bleats piteously, pushes against the wall, has uncertain, stiff or staggering gait, or convulsions, and finally paralysis. The head is hot, and the eye fixed, congested or sometimes rolled upward or squinted. Symptoms in the goat are nearly the same. The cœnurus disease is more gradual in its onset, and produces periodic paroxysms corresponding to the activity of the heads of the parasite when protruded into the brain substance. It is mainly confined to sheep of one year and under and that are kept where dogs have access.
Symptoms in Swine. Pigs may at first have a period of dullness or restlessness, the latter merging into active delirium. The patient champs his jaws, froths at the mouth and nose, sometimes vomits, squeals, raises himself with fore feet on the wall, walks round and round, or falls and rolls over, has tremors or convulsions.
Symptoms in the Dog. There may be preliminary indications of illness, anxiety, restlessness, irritability and a desire for seclusion. Vomiting may occur. This is liable to merge into prostration, a dullness of the special senses, utter inattention to calls, yet a disposition to resent any interference, a readiness to bite, at least to howl, when handled. Some will constantly howl or moan. The eye is fixed, the pupils dilated, the conjunctiva deep red, the head and roots of the ear are hot. The expression of the face is pinched and drawn, the muscles may twitch, the eyes roll, twitching of the neck or limbs may appear, and even epileptiform attacks. In exceptional cases the symptoms approximate to those of rabies, in the tendency to seek seclusion, to wander off, to bite on any interference, and even to gnaw the bars of the cage or any object within reach. After more or less of such excitement, the period of stupor, coma, paresis, or paralysis comes on, and the animal dies in a state of complete nervous prostration. In cases associated with the linguatula tænioides the sneezing, nasal discharge and nasal congestion, even in the early stages, betray the true character of the disorder.
The rabiform cases usually lack the intense heat of the head, the deep conjunctival congestion, the depraved appetite, the alteration of the voice, and the mischievous desire to attack without reason which characterize rabies.
Treatment. In all cases of phrenitis, quiet, darkness, and coolness are especially demanded. For the horse a roomy, loose box or a well fenced yard may be secured, and if he can be secured by a halter from a point above the level of the head and in the centre of the box it will obviate the increase of congestion by hanging of the head. The application of cold to the cranium in the form of wet cloths, ice bags or irrigation is always in order, and should be continued so long as heat of the head and other indications of cranial hyperæmia last.
In the horse suffering, as is so often the case, from narcotic poisoning an active purgative is one of the first considerations to clear away any remains of the poison from the prima viæ. An ounce of aloes may be safely given, as there is in this case little danger of superpurgation, and, to secure an even more prompt response, eserine (1½ grain) or barium chloride (½ drachm) may be given subcutem. Or an ounce or two of glycerine by the rectum might be used as a substitute for these last. The action of the purgative proves not only eliminant and therefore antidotal, but it is a most effective derivative from the brain. When the restlessness or excitement is very great we may use acetanilid, trional, sulphonal or some one of the many brain sedatives and antithermics. Sedatives, or anodynes like opium, which tend to increase cerebral congestion are dangerous.
Bleeding from the jugular or temporal artery, has been objected to on the ground that it tends to increase the exudate and therefore the pressure and cerebral anæmia. On the other hand it often proves of great value in vigorous, muscular and plethoric horses in temporarily lessening the blood pressure in the brain, and affording the walls of the overcharged capillaries an opportunity to resume a more normal tone and to control that very exudation which is so much dreaded. It is most effective in the early stages when little or no exudation has taken place and may then be pushed to the extent of producing a perceptible softening of the pulse (4, 6 or 8 quarts). Even in the advanced stages when exudation has led to stupor or coma a moderate and carefully guarded bleeding may favor reabsorption of the liquid exudate. In weak and anæmic cases in which general bleeding appears to be contra-indicated the shaving of the cranial surface followed by leeching or wet cupping can be safely resorted to.
Counter-irritants like bleeding are denounced and advocated by different practitioners. In cases of extreme hyperæsthesia where excitement and fever would be dangerously increased by their use, they must be discarded, or used only in the modified form of soothing hot fomentations to the extremities. Where there is less sensitiveness mustard poultices or pulp applied on the sides of the neck, or upon the limbs, or even more energetic blisters will be of great service.
After the action of the purgative the bowels may be kept free by calomel in ½ drachm doses twice daily and as much sulphate of soda as may be necessary.
Iodide of potassium (1–2 drs. twice a day) is beneficial as an antithermic a circulatory sedative, an eliminant, and probably at times as an antidote but it cannot be given while calomel is used. Certain it is that it often seems to act well in succession to the purgative, in cases of poisoning by ryegrass and leguminosæ.