112 ANNUAL REPORT OF THE Off. Doc. 



animals or persons bitten by rabid dogs do not become infected for 

 ttie reason that saliva is not always introduced into the wound. The 

 secretion may be scanty, the mouth of the dog may be rather dry, the 

 saliva may have been wiped from the teeth as they i>ass through 

 clothing or through the outer layers of the skin; the infectious ma- 

 terial mav be washed from the wound bv the flow of blood, or by 

 efforts at cleansing or by sucking, or it may have been destroyed by 

 the use of antiseptics. If a rabid dog bites a number of animals vv 

 quick succession, those last bitten are less exposed, because the in 

 fectious material on the teeth of the dog is in smaller quantity. All 

 animals, including man, have a certain amount of resistance to infec- 

 tion by the virus rabies as by the virus of other diseases, hence a 

 certain amount of virus may remain in the wound and still not pro- 

 duce infection, because the minimum quantity that is required to in- 

 fect that particular individual is not present. From these causes 

 it results that only about 15 per cent, of the people bitten by rabid 

 dogs are likely to develop rabies, even if not subjected to the 

 Pasteur treatment. Of domesticated animals bitten by rabid dogs, a 

 large percentage develop rabies approximately 50 per cent., and for 

 the reason that the wound receives less careful treatment, and be- 

 cause the body is not protected by clothing. 



Following infection from the bite of a rabid dog, at the expiration 

 of the period of incubation, symptoms occur that are, practically, the 

 same as those shown by the animal that conveyed infection. The, 

 so called, anti-hydrophobists claim that people that develop rabies 

 following the bite of a rabid dog are really infected with hysteria, 

 from fear. This alleged explanation fails to account for the occur- 

 rence of precisely the same condition in children or in infants who 

 have no fear of rabies, and in animals. 



Early diagnosis is of the utmost importance in the control of this 

 disease. Where it is suspected that an animal is afflicted with ra- 

 bies and, particularly, if a person or other animal has been bitten, 

 the suspected animal should be confined, and the course of the dis- 

 ease should be observed. It is often possible to confine suspected 

 dogs. If, however, the animal cannot be confined, it should be de- 

 stroyed. The head should be rem.oved with the two upper-most cer- 

 vical vertebrae; these should be thoroughly wrapped in parchment 

 paper, oil cloth or other impervious material, packed in ice, in a 

 large bucket, covered over, and sent to^the Laboratory of the State 

 Livestock Sanitary Board, corner 39th street and Woodland avenue, 

 Philadelphia. If it is found that the animal was afflicted with rab- 

 ies, a report to this effect is at once forwarded to the sender of the 

 material, and measures are instituted to prevent the spread of rab- 

 ies by animals that may have been exposed. 



It is possible now, by means of a microscopic examination, to de- 

 termine, within a few hours, whether a given animal was afflicted 

 with rabies, unless the animal was killed in the earliest stages of 

 disease before there was a chance for the characteristic lesions to 

 develop. The following report on the examination for rabies has 

 been prepared by Dr. John Reichel, who has been in charge of this 

 work for the State Livestock Sanitary Board during the past year: 



