This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
The symptoms of this disease are itching, burning, smarting, numbness of the part bitten, slight shivering, restlessness, no appetite for food, headache, frightful dreams, distress occasioned by the sight of water or any bright substance, spasm of the throat and shivering on attempting to drink, heat and contraction in the throat, great thirst, spasms of the whole muscular system, secretion of great quantities of viscid saliva, hoarseness, some fever, difficulty in breathing, great debility, death from exhaustion in two to six days. Cases are recorded, however, in which individuals have lingered a longer time, though in a state of such intense suffering that death would have been a grateful release at any moment.
This disease seems to have increased rapidly in modem times. This is probably due to the increasing number of dogs which are kept and allowed to run at large. The disease may be produced by the bite of a dog, wolf, polecat, or any other animal suffering with the disease. The period of incubation varies from a few days to a number of years. Cases have occurred in which the disease made its appearance ten or twelve years after the patient was bitten. The disease does not occur more frequently in hot weather, or the season known as "dog days," than at other seasons of the year, as is generally supposed. Statistics show that cases are fully as frequent in cold weather as in the summer season. It is probable that the disease may be developed spontaneously in the dog, but the most common way is by contagion through a bite. Human beings almost always contract the disease through the bite of a rabid dog; but experiments which have been made seem to show quite clearly that the saliva of a person suffering with hydrophobia will communicate the disease as well as the saliva of a mad dog or any other rabid animal. Fortunately but a small proportion of those who are bitten by rabid dogs arc inoculated with the poison. No more than one person in twenty-five suffers. It is necessary that the saliva should be introduced into the blood. This can only be done through abrasion of the skin. Cases have been reported in which horses have been inoculated by eating straw upon which a mad dog has lain. Another case is cited in which a man died of hydrophobia, having contracted the disease by using his teeth in untying a knot in a rope with which a mad dog had been tied.
It is probable that in some cases all the symptoms of hydrophobia may occur wholly through fear and without the individual having been infected. This is of course most likely to occur in persons who have been bitten.