Rabies in Dogs and Other Animals

We now rapidly, and for a little while, retrace our steps. What is the cause of this fatal disease, that has so long occupied our attention? It is the saliva of a rabid animal received into a wound, or on an abraded surface. In horses, cattle, sheep, swine, and the human being, it is caused by inoculation alone; but, according to some persons, it is produced spontaneously in other animals.

I will suppose that a wound by a rabid dog is inflicted. The virus is deposited on or near its surface, and there it remains for a certain indefinite period of time. The wound generally heals up kindly; in fact, it differs in no respect from a similar wound inflicted by the teeth of an animal in perfect health. Weeks and months, in some cases, pass on, and there is nothing to indicate danger, until a degree of itching in the cicatrix of the wound is felt. From its long-continued presence as a foreign body, it may have rendered the tissue, or nervous fibre connected with it, irritable and susceptible of impression, or it may have attracted and assimilated to itself certain elements, and rabies is produced.

The virus does not appear to have the same effect on every animal. Of four dogs bitten by, or inoculated from, one that is rabid, three, perhaps, would display every symptom of the disease. Of four human beings, not more than one would become rabid. John Hunter used to say not more than one in twenty; but that is probably erroneous. Cattle appear to have a greater chance of escape, and sheep a still greater chance.

The time of incubation is different in different animals. With regard to the human being, there are various strange and contradictory stories. Some have asserted that it has appeared on the very day on which the bite was inflicted, or within two or three days of that time. Dr. Bardsley, on the other hand, relates a case in which twelve years elapsed between the bite and the disease. If the virus may lurk so long as this in the constitution, it is a most lamentable affair. According to one account, more than thirty years intervened. The usual time extends from three weeks to six or seven months.

In the dog I have never seen a case in which plain and palpable rabies occurred in less than fourteen days after the bite. The average time I should calculate at five or six weeks. In three months I should consider the animal as tolerably safe. I am, however, relating my own experience, and have known but two instances in which the period much exceeded three months. In one of these five months elapsed, and the other did not become affected until after the expiration of the seventh month.

The quality and the quantity of the virus may have something to do with this, and so may the predisposition in the bitten animal to be affected by the poison. If it is connected with œstrum, the bitch will probably become a disgusting, as well as dangerous animal; if with parturition, there is a strange perversion of maternal affection — she is incessantly and violently licking her young, continually shifting them from place to place; and, in less than four-and-twenty hours, they will be destroyed by the reckless manner in which they are treated. In both cases the development of the disease seems to wait on the completion of her time of pregnancy. It appears in the space of two months after the bite, if her parturition is near at hand, or it is delayed for double that time, if the period of labour is so far distant.

The duration of the disease is different in different animals. In man it has run its course in twenty-four hours, and rarely exceeds seventy-two. In the horse from three to four days; in the sheep and ox from five to seven; and in the dog from four to six.

Also read: Dog Health Information.