RABIES 313 



no justification unless the period is extended to include the 

 entire year. 



The incubation period varies considerably in lenirth, de- 

 pending upon the location and extent of the bites. The 

 symptoms are not apparent until the central nervous system 

 is involved. The rapidity with which this will occur is de- 

 pendent on the distance of the bite from the brain. The 

 extent of the bite is aNo of importance in determining the 

 rate at which the disease progresses. The average periods 

 of incubation are as follows: 



Man .............................. IM .lays 



'2\ is 



< ;its ............................... 14 2s 



Pig8 .............................. 14 21 



Sheep ............................. 21 - -JS <lay^ 



The virus may remain dormant after its introduction into 

 the tissues for a varying period of time, thus delaying the 

 development of the symptoms for months and possibly years 

 after the bite is inflicted. 



Symptoms. Rabies is generally divided into two forms, 

 furious and dumb. In the lirst the animal is irritable and 

 bites nearly every object with which it comes in contact; 

 in the second the muscles of its jaws are paralyzed early 

 in the attack, and, being unable to bite, the animal remains 

 more quiet. The two forms of the disease represent the ex- 

 tremes, and all gradations are to be noted between them. 

 The saliva from a case of dumb rabies is just as dangerous 

 as that from a case of the furious type. The furious type 

 passes into the dumb type as the disease progresses, owing 

 to the paralysis of the muscles. 



The furious type is marked by symptoms of nervousness. 

 The animal may be more restless or more affectionate than 

 usual, seeking to lick the hand or face. If an abrasion of 



