Synonyms:—Rabies; lyssa; la rage.

Definition:—A specific, highly infectious disease, originating in carnivorous animals, naturally in wolves and dogs, and thence conveyed to other animals, and to man. Its characteristics are an apparent dread of water, from which fact the name is derived; great restlessness and nervous excitability and spasms of the larynx and pharynx; ultimately paralysis, delirium, coma and usually death. A small percentage only of the cases recover.

Etiology:—The virulence of the disease is exercised upon the central nervous system, but the cause is not determined. In diligent search for a micro-organism several investigators claim to have found a specific germ, and Memmo claims to have reproduced the germ, and by the inoculation with it, of dogs, birds and rabbits, to have successfully reproduced the disease.

Pasteur reproduced the disease by inoculating healthy animals with the actual diseased brain substance. The poison is found in the nervous tissue and in the saliva, but is not found in the blood nor urine. As commonly met, a dog in which the disease has developed without known cause, has bitten other dogs, small domestic animals, cows, horses or children, before it was known that it was infected. In a few cases an actual epidemic has been spread in a community from this original cause. In Russia and other countries where wolves abound in large numbers it originates in a single animal and is conveyed ultimately to a pack and thence to other animals, wild and tame. Cats, skunks and small rodents have been infected and have spread the disease. A man suffering with the disease has bitten and thus infected another. It is always conveyed by direct inoculation through a wound or abrasion.

There are isolated cases in every large city every year. If the animal is killed before it inoculates others, there may be but a single case, and in any event but few cases occur from a single cause, and then the disease disappears again. The disease may be immediately stamped out by muzzling all dogs and killing those at once which have been bitten, although not above twenty per cent of those bitten will develop the disease.

Symptomatology:—The period of the incubation of the disease may extend from two weeks to two years, and claim has been made of the occurrence of the disease several years after infection. If the rabid animal in the virulent stage of the disease inflicts a direct punctured or lacerated wound, and more especially if a child instead of an adult be bitten, the premonitory symptoms of the disease may appear within a few days. These symptoms, which will last only from two to perhaps four days, are great mental depression and apprehension, especially in one who realizes the danger. The part injured becomes reel, slightly inflamed and itches, and sharp pains radiate from it, giving the patient constant uneasiness. The wound, which may have healed naturally, may open, vesicles may form around or upon its edges, and the contiguous lymph glands may become swollen and tender. With these symptoms restlessness increases and after four or five days difficulty in swallowing is apparent and there is evident embarrassment of the respiration.

A pathognomonic symptom is the spasm of the pharynx that occurs even upon sight of water, and desire for water—thirst—is an early and most aggravating accompaniment. Great nervous excitement rapidly develops, the jaws snap together, as if the patient was biting at all objects, and he often is constantly spitting. Hyperesthesia to a marked degree is a common symptom with muscular spasm. There will be paroxysms, in which all symptoms are exaggerated, to be followed by periods of quiet, and perhaps dulness. The fever is not high, seldom rising above 102° F., and more often absent entirely. The pulse is irregular, usually rapid in the latter stages. The mind early becomes affected, and in some cases suicidal tendencies develop. The disease runs its course to a usually fatal termination in from eighteen hours to five days.

A paralytic form of the disease develops in rare cases, usually where there has been serious laceration, and where the bites were deep. This form terminates fatally within twenty-four or thirty-six hours. Paralysis appears at the seat of the injury and extends toward the nerve centers until the respiratory centers are affected. Symptoms of this character sometimes terminate a case which has previously exhibited all the premonitory evidences.

Diagnosis:—The diagnosis is usually made through knowledge of the injury having occurred and by the pharyngeal spasm. The fear of water and great apprehension are also apparent. The real condition must be differentiated from hysterical rabies and from tetanus. The hysterical form may develop from solicitude, and all evidences will abate upon use of profound sedatives or nitroglycerin or nitrite of amyl. Tetanus has tonic spasm of the jaws without intermissions and no great degree of anxiety.

Treatment:—When the disease has fully developed no known method of treatment has as yet successfully combated it. Pasteur's method of inoculation is the only known method of prevention, and this occasionally fails. Pasteur, by long continued investigation, determined the fact that if the virus of hydrophobia were injected into a rabbit, and from rabbit to rabbit, the virulence of the poison increased and thus shortened in each consecutive individual the period of incubation. The virulent spinal cords of these animals were preserved for a definite time in dry atmosphere, when the virulence would abate. An exact difference in degree of virulence was determined and definite emulsions were prepared from these cords. From persistent experiments upon dogs a course was determined upon for man, which is now generally adopted. This course is to inoculate the patient as soon as possible after the infection with a mild emulsion, then at regular intervals with those emulsions of increasingly greater virulence, until complete immunity is acquired. A more intense course is adopted in cases where much time has elapsed since the bite was inflicted, or where the evidences are that the bite was directly inflicted upon a bare surface, than in those cases where the bite was not severe, and was inflicted through some medium.

As a result of this treatment in the Pasteur institute in Paris the mortality is only 0.5 per cent. In the New York institute it is a little greater than 0.6 per cent. In the Chicago institute, under Doctor Lagorio's careful management, during the past fifteen years twenty-four hundred patients have been treated, in whom there was sufficient evidence that there was actual infection. Of these only seven have died—a mortality of less than 0.3 per cent.

It is always advisable that when an individual has been bitten to thoroughly cleanse the abraded surface and to widely open a punctured wound. These should be immediately cauterized with carbolic acid, nitric acid or caustic potash. Severely lacerated wounds should have all torn and mutilated tissue removed and the lacerated surfaces thoroughly cleansed and cauterized. Incised wounds should not be allowed to close for perhaps four weeks if the animal is proven to be rabid. If the wound be on an extremity it is well to apply a tourniquet between the wound and the body until the wound is cauterized. When there is doubt as to the origin of the disease In the animal the patient should be sent immediately to a Pasteur institute.

We have specific remedies that will modify the symptoms to an extent, and it is our duty to ameliorate the distress by every means in our power. Where an individual is bitten by a dog proven to be rabid, each animal bitten should be kept isolated until the disease develops characteristically. When all proofs of the disease are made and all the evidences are satisfactory, the animal should be shot, and other animals should be carefully inoculated with portions of the brain structure, or tissue from the cord, to determine that the disease is transmissible from it.

Echinacea must be thoroughly tested as a remedy in this disease. In patients that cannot be taken to a Pasteur institute the wound should be thoroughly injected with full strength echinacea, as well as the surrounding tissue. The wound should be dressed with gauze, saturated with the remedy and covered with rubber protective. From half a dram to a dram of the remedy should then be given internally every two hours. If any symptoms of the disease appear the wound should be reinjected and dram doses should be given every hour. We have the best of reasons for believing that the agent will be of service. It has antagonized to a greater or less degree the effects of every organic poison where it has yet been used. It has been successful in tetanus without doubt, and has saved the lives of hundreds bitten by rattlesnakes and other poisonous reptiles and insects. It is at least our duty to give it a most thorough trial and to conduct all investigations and experiments in the most scientific manner, that we may be enabled to prove or disprove its influence in this disease.

The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.