Other Findings About Rabies

The following observations and experiments respecting rabies, by Dr. Hertwich, Professor at the Veterinary School at Berlin, are well worthy of attention.

1. Out of fifty dogs that had been inoculated with virus taken from a rabid animal of the same species, fourteen only were infected.
2. In the cases where inoculation had been practised without effect, no reason could be assigned why the disease should not have taken place. This consequently proves that the malady is similar to others of a contagious nature, and that there must exist a predisposition in the individual to receive the disease before it can occur. In one experiment, a mastiff dog, aged four years, was inoculated without exhibiting any symptoms of the malady, while seven others, who had been inoculated at the same time and place, soon became rabid. Several of these animals had been inoculated several times before any symptoms showed themselves, while in others, on the contrary, once was sufficient.
3. It appears that in a state of doubtful rabies, one or two accidental or artificial inoculations are not sufficient to create a negative proof of its existence.
4. This disease has never ben communicated to an individual from one infected by means of the perspirable matter; this, therefore, is a proof that the contagious part of the disease is not of a volatile nature.
5. It does not only exist in the saliva and the mucus of the mouth, but likewise in the blood and the parenchyma of the salivary glands; but not in the pulpy substance of the nerves.
6. The power of communicating infection is found to exist in all stages of the confirmed disease, even twenty-four hours after the decease of the rabid animal.
7. The morbid virus, when administered internally, appears to be incapable of communicating this disease; inasmuch as of twenty dogs to whom was given a certain quantity, not one exhibited the least symptom of rabies.
8. The application of the saliva upon recent wounds appears to have been as often succeeded by confirmed rabies as when the dog had been bitten by a rabid animal.
9. It cannot now be doubled that the disease is produced by the wound itself, as was supposed by M. Girard of Lyons, not by the fright of the individual, according to the opinion of others, but only from the absorption of the morbid virus from its surface.
10. Several experiments have proved to me the little reliance there is to be placed on the opinions of Baden and Capello, who believe that, in those dogs who become rabid after the bite of an animal previously attacked with this disease, the contagious properties of the saliva is not continued, but only exists in those primarily bitten.
11. During the period of incubation of the virus there are no morbid, local, or general alterations of structure or function to be seen in the infected animal; neither are there any vesicles to be perceived on the inferior surface of the tongue, nor any previous symptoms which are found in other contagious diseases.
12. This disease is generally at its height at the end of fifty days after either artificial or accidental inoculation; and the author has never known it to manifest itself at a later period.
13. It is quite an erroneous idea to suppose that dogs in a state of health are enabled to distinguish, at first sight, a rabid animal, inasmuch as they never refuse their food when mixed with the secretions of those infected³.

Also read: Dog Health Information.