In all cases of suspected hydrophobia it is best not to kill the dog; but if, by accident or design, • the death is accomplished the body should at once be sent to the health board au thorities for a confirmation of the diagnosis. The characteristic changes, as described by Neils in 1900, consist in minute alterations in the spinal ganglion cells, especially in a proliferation of the endothelial cells of the ganglionic cell capsule. These changes are considered char acteristic of this disease and are not known to occur in any other affection. The general treat ment is both prophylactic and remedial. All stray dogs should be destroyed; or, if they have bitten anyone, they should be imprisoned and watched. It is best to have dogs muzzled or held in leash. In Germany muzzling has en tirely eradicated hydrophobia. London in 1889 had 176 cases of hydrophobia. Muzzling was made compulsory, and in 1890 the number of cases of rabies had fallen to 44; in 1891 to 28; and in 1892 to 3. The muzzling was then al lowed to lapse, owing partly to the sentimental agitation of many so-called lovers of dumb ani mals, and the cases of rabies increased, 25 per sons dying of the disease in five years, while 174 patients were sent for treatment to the Pasteur Institute.
The direct treatment of the wound causing rabies is important. The poison seems to diffuse slowly, so that, if a ligature is promptly placed about the limb on the body side of the wound, a suction-cup or direct sucking may extract all of the virus. In the non-abraded mouth the virus is not very poisonous. If the wound is deep it is sometimes wise to make immediately a free incision, permitting the flow of blood to wash away the virus and also allowing a more open surface for the actual cautery. One of the best cauterizing agents to use is strong nitric acid. The after-treatment will depend very largely on the promptness and thoroughness of the first treatment. If there is reason to believe that the early cauterization was ineffectual, the Pasteur method of treatment (see PASTEUR, Louts) is advisable. This is a complicated method which was elaborated by Pasteur about 1880. He found that the virus was present in
the spinal cord of a rabid animal; that its viru lence slowly diminished after the death of the animal; that the virus could be artificially weak ened by passing it through a series of monkeys until it was powerless; and that, conversely, this virulence could be restored by inoculating the attenuated virus in a series of rabbits. Thus Pasteur made a weak virus and a strong one at will, and he later produced immunity to the virus by the use of his attenuated material. The final plan that was adopted was to kill a rabbit by means of his strong virus, remove its spinal cord, cut this up into short sections and dry it for varying periods of time. In this manner he secured a graded series of cord-sec tions of gradually decreasing virulence. These were emulsified in salt-solution and used to in ject into animals or man, the weaker virus be ing first used' and the stronger later. Two methods are now in vogue — the simpler method, for the less severe bites, in which 19 injections are given in 14 days; and the in tensive method, for the severe bites about the neck and face and the large nerve-trunks, in which 28 injections are administered in 21 days. The serum-treatment of the disease is also rapidly becoming a possibility. Two Ital ian investigators, Tizzom and Centanni, have made an anti-rabic serum that promises some thing for the future. For the present, however, the Pasteur method is the most reliable. It is certainly harmless and is worthy of trial. The results are assuring and the statistics, to most minds, convincing. It should not be forgotten that there is a false hydrophobia which is of purely hysterical origin, during an attack of which some patients have died. Consult Brad ford, 'Two Lectures on Rabies' (Lancet, 3 March 1900); 'Hydrophobia in Germany' (Hygienist he Rundschau, 7 Nov. 1899) ; 'Re port of Select Committee of the House of Lords on Rabies in Dogs' (Blue Book, 1887); Medical News (15 Aug. 1903) ; Sixteenth An nual Report Bureau of Animal Industry (1899).
See HYSTERIA.