An introduction to Rabies (Hydrophobia)

Dr Asem Suresh Kumar Meitei
Contd from previous issue
Towards the end of the incubation period and a few days before the appearance of characteristics symptoms, a number of prodromal or premonitory symptoms set in. In case of dog, it changes its disposition, becomes strange in its behavior and capricious in its habits. It frequently hides in dark places avoid light and noises, and when is is called it obeys unwillingly as if it has been doing something wrong. Sometimes, it crouches towards its master and jumps about in an unusual way. The dog often appears to be uneasy, lying down and getting up alternatively at frequent intervals. It walks in a peculiar manner and often snaps in the air or towards it body at imaginary flies or fleas. At times it suddenly becomes alarmed and barks at nothing.                            
The second stage is the stage of furious rabies or true rabies. This stage is known as stage of irritation, stage of mania or Stadium irritans. After a few days, the reflex irritability of the affected dog becomes considerably increased. It may snap anybody or anything within its reach on the slightest disturbance and without any provocation. I may appear quite friendly, but is easily irritated, especially if restrained. If held, it will attempt to break away and if not released at once will bite savagely. At first, it becomes annoyed with strangers only, but in course of a day or two, it shows resentment at the friendly attention of its regular associates. Such external stimuli as strong light, noise, and touch may easily startle the animal and cause it to jump up. In the majority of cases, the appetite becomes depraved and the patient refuses its normal food but readily chews foreign objects of any kind within its reach, including its own faeces. Swallowing becomes more and more difficult and finally impossible. Sometimes frequent vomition occurs and salivation becomes progressively more and more profuse. In the majority of cases, the patient develops a severe thirst, but it always finds great difficulty in drinking. Some animals have an abnormal sexual desire.
In the course of one to three days, a violent rage sets in. The dog fiercely chews any object it can hold of and furiously tears it to pieces, if possible. It becomes more and more restless and manifests an insuperable desire to get away from its surroundings. If it is tied up, it tries to break loose and if it is shut up in a cage, it jumps viciously at the bars, often snapping with such violence at the bars that it breaks its teeth. The nature of the object that it bites is immaterial and it will grab a red-hot iron or a burning coal as readily as a piece of rag. An attack of rage is usually interrupted by a arable intervals of depression and at times a raging dog may drop down exhausted and unconscious. Soon after consciousness returns, the dog rises again, but remains standing with terror stricken and furious expression on its face until a fresh attack of mania sets in.
If the mad dog breaks loose, it is inclined to wander about aimlessly and seldom returns home, or it may return in an extremely exhausted condition with its hairs ruffle and its skin often covered with bite wounds. A rabid dog is extremely aggressive and if it should encounter another dog during its wanderings it furiously attacks the other dogs without any cause. Although, a mad dog is always more aggressive towards other dogs, it may attack any species.
The third stage of rabies is known as paralytic stage or Stadium paralyticum. In the course of a few days, symptom of paralysis appear in different parts of the body, the muscle of pharynx and larynx being generally affected  first, and later , the muscles of locomotion. As a result, the dog makes a peculiarity hoarse sound or howl, and swallowing becomes difficulty or impossible. There is loss of irritability and tendency to bite will disappear. Nevertheless, violent and less frequent and the patient becomes dull and extremely depressed. The paralysis becomes progressively worse. As a result of paralysis of the muscles of mastication and of the tongue, and eyes, the mouth is kept wide open, the tongue hangs out, the eyes have a squinting appearance, and there is profuse secretion of saliva. Finally, the paralysis extends to the limbs and the tail and complete incoordination of the movement sets in. The dog becomes dumb and unable to bark and bite. It can no longer rise, lies down with a great deal, and becomes thin, emaciated and weak before it dies.                                                                                                      
As there is generally no thermal response, it is unnecessarily and also too dangerous to take temperature.
The symptoms manifested by the different species of animals do not vary very much, but the symptoms sometimes vary considerably in different individuals. Most animals show symptoms of the three types to a variable degree, and the duration of one stage may be lengthened or shortened at the expense of another. Occasionally, an animal, including dog, may not show the stage of mania (furious form). Or, the manic phage may be inconspicuous. Such animals show the paralytic form of rabies, without showing the symptoms of the furious form. Animals showing such type of rabies are considered more dangerous for man.
Animals suffering from rabies are without fear, and rabid wild animals have often been found fearlessly invading a farm-yard or human inhabitations where they furiously attack domestic animals and man.
Species Variations
Cats: Cats appear to be even more vicious than the dogs and readily assault both man and animals. They frequently attack from behind and generally inflict their bites and scratches on the face of the victims.
Herbivorous animals: Herbivorous animals may also be aggressive, particularly towards dogs, but they are less inclined to bite or attack other animals. The ox may tear up the ground and furiously throw its head back. The main symptoms in cattle are acute abdominal pain, straining, salivation and bellowing. Death may occur in five days.
Cattle: Among farm animals, cattle are most commonly affected. Cattle with furious rabies can be dangerous, attacking and pursuing humans and other animals.
Tenesmus, with paralysis of the anus, resulting in the suckling in and blowing out of air usually occurs late in the incoordination stages just before the animal goes down. Drooling of saliva is one of the most constant signs. The so-called yawning movements are more accurately described as voiceless attempts to bellow. Paralysis follows; the animal goes down and is unable to rise. Bulls in the mild or paralytic stage often have paralysis of the penis. Death usually occurs 48 hours after recumbency develops and after a total course 6 to 7 days. Common Lactation ceases abruptly in dairy cattle. The usual placid expression is replaced by one of alertness. The eyes and ears follow sounds and movement intently.
(To be contd)