Chorea is characterized by involuntary, tremulous, and irregular motions or twitchings of those muscles which, in the healthy state, are under the influence of the will. One or several groups of muscles may be thus affected. There are several causes which predispose dogs to this disease. It is most frequent in young dogs, although it may, in rare cases, appear at a more advanced age. Debility, arising from want of food, previous illness, or any other cause that induces constitutional weakness; close confinement or overcrowding; and inherited peculiarities of temperament or constitution, may be reckoned amongst the predisposing causes.

The exciting causes are le33 obscure. Worms, disordered states of the digestive organs, and accumulations of vitiated intestinal secretions, are probably the most frequent. Injuries to some part of the nervous system, such as blows on the head, may excite chorea. By far the most common, however, is a previous attack of distemper. Its occurrence has no relation to the severity of the distemper, as it may come on after a mild attack. It may occur either as a complication, or as a consequence of distemper.

The nature and seat of chorea are undecided points. Its occurrence in youth, and in connexion with debility and distemper, lends countenance to the probability that the first condition is depression and excitability of the nervous system - two states which favour the production of irregular muscular action, under the unhealthy stimulus of excentric irritation, such as worms, etc. There are other cases in which the brain, or the cerebro-spinal system, is alone involved. In one case, Youatt found spiculae of bone projecting from the parietal bone, and so keeping up meningeal irritation. It often happens, however, that no structural change can be discovered in any part of the nervous system; or, indeed, in any part of the body.

Symptoms

The spasmodic movements of chorea are either partial or general; usually the former. One leg or shoulder is jerked in an irregular way at fixed intervals. For a longer or shorter period, the disordered movements affect only one limb, or both legs are affected alike; in which case, when the dog is standing, the head and shoulders are bobbed down at each movement. Sometimes the hind-legs only are attacked; or the entire body; or the muscles of the eyelids, or those of the face. These characteristic appearances vary not only in extent, but in degree, from simple catching, up to unceasing and exhausting motions, which the animal has no power to prevent or diminish. They continue either in the upright, or the lying position; and if they cease during sleep, the sleep is disturbed and unrefreshing. In many cases, sleep does not affect the continuance of these movements. The dog expresses, by moans and cries, the distress felt from his tormenting sufferings. Absolute repose is unknown to him from first to last. His temper gets irritable, especially in severe and prolonged cases; and he becomes thin and weak. In some cases, the general health is unimpaired; in others, broken down by want of rest and undue expenditure of nervous force. In some cases, the above state continues without abatement; in others, the spasmodic movements become less severe or extensive, and recovery appears at hand, but he presently relapses into his old state under the excitement of mental emotion, or a new disease. In addition to the foregoing symptoms, there may be found as precursors, or accompaniments, certain indications which point out disturbance of the digestive functions: such as, variable appetite, costive bowels, tumid abdomen, foul tongue, etc. The presence of worms should be inquired into. Chorea may terminate in true convulsions, fits, or paralysis agitans. In the latter case, the movements resemble those of chorea, but they continue invariable during sleep, are of a tremulous character, affect the whole system of voluntary muscles, and are aggravated by whatever excites alarm or fear. In chorea, the dog is quite conscious, and his power of volition remains good. The choreic movements do not occur in paroxysms; and the muscles which are affected with unnatural and unsteady movements are still under the influence, but not under the absolute control of the will. There is no febrile excitement whatever.

Treatment

The following remedies are respectively indicated by the subjoined symptoms: -

Nux vomica:* confined bowels, impaired appetite, and the other symptoms of stomachic disorder; trembling or convulsive jerking of the limbs, or of sets of muscles; irritability of temper, etc.

Ignatda: convulsive movements of the limbs, eyes, eyelids, or muscles of the face, aggravated by fright.

Belladonna and Cuprum acetieum are sometimes productive of benefit.

Food, Etc

Chorea is one of those diseases that are as much benefited by hygienic means as by purely medicinal remedies. The food must be particularly attended to. Boiled rice, with beef-tea and no solid meat, are the best, as being bland and unirritating to the stomach. Bread-sops and oatmeal gruel may be allowed as a change. Bones are out of the question. The dog's head should be steadied, if necessary, whilst he is eating and drinking; the chief point, however, is to give small quantities of the suitable food, unheeding the dog's voracious appetite. A cold douche-bath is often beneficial.

Youatt, in his work on the Dog, gives a case in illustration of the then treatment of chorea. During five months, the unfortunate subject underwent the usual round of drugging. He had several "strong" emetics, several "strong" doses of salts; * setons were put in, and kept in for several weeks; tonic and distemper-balls were given in profusion. In about four months after this treatment had been going on, the dog was seized with a severe fit. A "physician" urged bleeding; the dog was accordingly bled twice, secundum artem; and tonics, emetics, purgatives, and the seton again resorted to afterwards. "After four doses (of salts) had been given, it was impossible to force any more upon him." The poor dog had some common sense in him! He was then sent "into the country." Six months afterwards he was brought back; and the following cruelties were practised on the poor brute: "His owner at length consented that the actual cautery should be applied to his head. The searing-iron for doctoring was used, and applied red-hot to the centre of the head. It was exceedingly difficult so to confine the dog as to make the application effectual without destroying the skin. Under the influence of the sudden violent pain, he wandered about for more than two hours, and then the spasms returned with greater force than usual. He refused all food."

* For the dose, etc., refer to the "Introductory Remarks".

* "He was dreadfully ill after taking the salts; perhaps they were not genuine. For two days he panted sadly; refused his food, and vomited that which was forced upon him. His muzzle was hot; he could scarcely stand; he lost flesh very rapidly."

Whether the salt was genuine or not, these are just the symptoms which attend an over-dose.

"We determined to try the cautery to its full extent. We chained him up in the morning, and penetrated through the skin with the budding iron. The spasms were dreadfully violent, and he was scarcely able to walk or to stand. This gradually subsided, and then he began to run round and round, and that increased to an extraordinary velocity; he would then lie for a while with every limb in action. The owner then yielded to all our wishes, and he was destroyed with prussic acid."

Such a catalogue of heartless and cold-blooded cruelty is a disgrace to the profession, and happily unexampled in the annals of veterinary medicine. Verbeyen states that the seton, vesicatories to the head, frictions with turpentine, and cantharides, were not productive of the happiest results in Youatt's hands; that he has tried the seton, but it aggravated the disease; and that counter-irritation generally is either useless or hurtful. Hekmeyer was obliged to remove a seton that he put into a choreic dog. Yet in the face of this overwhelming evidence against the use of the seton, etc., in chorea, "Stonhenge" advises a seton in the neck!

Mayhew orders Nux vomica in pill along with potash, hyoscyamus, quassia, and gentian; and speaks of it as "the most important ingredient." He goes on to say, "Nux vomica must be used in very minute doses, to be entirely safe - from a quarter of a grain to a male pup, to two grains to the largest animal. That quantity must be continued for a week, four pills being given daily; then add a quarter of a grain daily to the four larger pills, and a quarter of a grain every four days to all the smaller ones: keep on increasing the amount, till the physiological effects of the drug, as they are called, become developed. These consist in the beast having that which uninformed people term a 'fit.' He lies upon the ground, uttering rather loud cries, whilst every muscle in his body is in motion. Thus he continues scratching, as if it was his desire to be up and off at a hundred miles an hour. No sooner is he rid of one attack than he has another. He retains his consciousness, but is unable to give any sign of recognition.....I have beheld the physiological effect of nux vomica, but cannot recollect many instances in which 1 could date amendment from its appearance" The italics are mine. What is the use of poisoning the dog with excessive doses of nux vomica, instead of curing his chorea? If this drug be really indicated, as it often is, small doses will cure the disease without running the risk of killing the patient.