Emaciation, weakness, exhaustion, lethargy and paralysis appear early, the victim remains down, or, if raised, moves weakly and unsteadily and no longer pays attention to noises nor blows. Death may ensue from the first to the sixth day.
Symptoms in Rabbits. Experimental cases in rabbits are now very common and usually assume the paralytic or lethargic type, there is weakness in the hind parts, advancing in a few hours to paraplegia, the fore limbs may be used for a time while the hind are flaccid and dragged behind, or the animal lies on the sternum and belly with the head sunken and resting on the feet, or he lies extended on his side, in a state of insensibility. In the early stages he may still masticate, with froth collecting on the lips, but there is difficulty in swallowing. If a foot is pinched it is drawn up often with a cry. The bowels are torpid though a few small, round, hard pellets are sometimes passed or a little urine. Incubation is shorter than in the dog, and the virus retains this habit when inoculated on other animals.
In the experimental cases in the Anti-rabic Institute in St. Petersburg, Helman found that the rabbits inoculated with virus from dogs having furious rabies, contracted furious rabies, while those inoculated from the less furious type of street rabies had the disease in the dumb form.
Symptoms in the Guinea-pig. In this animal as in the rabbit the disease has been mainly seen in the experimental form, and has assumed the paralytic type. It trembles, moves stiffly or weakly, lies most of its time and passes rapidly into paralysis. There is usually no tendency to bite, yet Peuch in a case of intraocular inoculation from a rabid cat observed the most violent excitement, loud hoarse screaming, bounding in different directions, biting of the wires of the cage, and other manifestations of violent rabies. In both forms there are liable to be convulsive movements of the jaws, accumulation of frothy saliva, and a free discharge of urine.
Symptoms in Birds. Chickens bitten by mad dogs have been seen to prove restless, erecting the feathers and moving aggressively toward man or dog or phantoms of their imagination and attacking with bill or spurs or both. This, however, rapidly advances to paralysis and death. In cases due to intracranial inoculation on the other hand, somnolence, lethargy, or coma appeared early, and was quickly followed by paralysis. This affects especially the legs and neck. Recoveries are common and the animal is thereafter immune. Subsidence, with complete intermission of symptoms, is more common than in rabbits, the disease reappearing later, and perhaps finally ending in recovery.
Symptoms in Wild Carnivora. The rabid wolf, fox, jackal, hyena, coyote, ferret, polecat and skunk lose their fear of man, and approach and attack him either in field, village or city. The disease has its furious and paralytic stages as in the dog, and the animals attack according to their nature, wolves being dangerous from flying at the face and throat, and skunks from stealing up and biting without warning.
Symptoms in Man. After the period of incubation prodromata may be present, or there may be suddenly and without any premonition, violent spasms of the pharynx and inability to swallow. The premonitory symptoms when present consist in irritability of the cicatrix which becomes red or blue, swollen, itchy or pricking, and an aura or shooting pain may extend from this toward the heart. There is anxiety, sighing, tremor, restlessness impelling to frequent change of place, insomnia, disagreeable or painful dreams, weariness, and gloomy forebodings. The face is pale and drawn, and the eyes wander or have a look of apprehension. There is some fever and often marked thirst, and the attempt to swallow rouses slight spasm or a sensation of tightness in the throat. The fauces, pharynx and eyes are congested, reddened and it may be swollen. Pulse and respiration are both quickened, the inspiration being often prolonged and sighing, and the expiration sobbing. At first the intellect is unimpaired; there is no illusion nor hallucination.
In cases in which premonitory symptoms are lacking, violent spasms of the throat and chest are commonly roused by an attempt to drink and this is so painful that the patient cannot again be induced to try. After this any suggestion of drinking, the offer of drink, the noise of trickling water, the sight of water, the sight of a vessel in which the water was contained, or even of a clear shining surface of glass or metal is likely to bring on a paroxysm. This hydrophobia is peculiar to man being rarely seen in rabid animals. During a paroxysm dyspnœa is extreme, respiration is gasping or sighing, and in the attempt to dislodge the tenacious mucus which is present in the throat, hoarse or shrill inarticulate sounds are emitted which have been supposed to resemble the bark of the dog. There is a sense of closure of the throat and of rising of the stomach, and retching or even vomiting may ensue. Hyperæsthesia, reflex irritability, and exaltation of the special senses, now become extreme, so that a paroxysm may be brought on by the slightest disturbance, a current of air, a bright light, the rustling of a dress, the noise of a footfall, the noise even of talking, or a slight touch. The “tendon reflex” and skin reflex are often much encreased. During a paroxysm there are muscular trembling and clonic spasms,—sometimes opisthotonos. The intervals of complete relaxation, however, serve to distinguish from tetanus. The face is red and drawn, the eyes congested and sometimes squinting, the pupils dilated and the expression one of suffering, apprehension and horror. Mental disorder appears sooner or later, the speech is disconnected, with indication of delusions from which the patient may at first be recalled by the attendant. There is, however, a constant disposition to be reticent, morose and above all, suspicious, as shown by the absence of a direct look, and the frequency of side glances as though in expectation of a hidden danger. This may even rise to mania, the patient charges those about him with having caused his sufferings, or with conspiracy to injure him, and he may seek to defend himself with hands, feet, teeth or any available object. The necessary restraint aggravates and prolongs the attack. On its subsidence the patient collects his scattered senses, regrets, apologizes, and warns against future occurrences of the same kind which he realizes to be beyond his control. Sometimes the delusions continue during the remission as well. Sexual excitement is common in man as in animals.
The convulsive paroxysms may last ½ to 1 hour, and they tend to encrease in duration and force. A violent paroxysm may cause sudden death from asphyxia or apoplexy.
Sooner or later exhaustion and paresis appear. The convulsions become gradually weaker, the reflex irritability and hyperæsthesia abate, and the patient may become once more able to swallow, but an ascending paralysis, beginning in the limbs spreads over the body and death occurs in from one to eighteen hours. In the paralytic stage there may still be slight jerking of the muscles, or tremors, but violent convulsion no longer occurs, and there is extreme prostration, with hurried, rattling breathing, small, weak, irregular pulse and finally, stupor and coma.