474 Eabies. 



incubation is: in horses 46%, in cattle 70, in dogs 22, in swine 26, in go^ts 14, 

 and in sheep 26% days. [Finally, Bchuder found out of 395 carefully ol)serYe4 

 cases of rabies 21 (5.3%) where the period of incubation was 3 to 7 months.- 



Unusually long periods of incubation have been observed: in horses, by 

 Saikowitsch 17 months, by Virdg 18, Oosswinter 20, Bahr 21, Swain 25 months; 

 in cattle, by Szabo 323 days (bite in the snout), Mieckeley 327 days, Leipert 19 

 months and 21 days, and by Kalt 23 months. The reports relating to periods of 

 more than 2 years, however, must be accepted with reservation, as a new infection 

 may have occurred in the meantime. 



After artificial infection, dogs develop the disease 13 to 19 days after sub- 

 cutaneous injection, 10 to 15 days after subdural injection; rabbits show symptoms 

 12 to 21 days after subdural injection, but in exceptional cases later, occasionally 

 only after 43 days. After a series of inoculations, the period of incubation following 

 the subdural injection may be shortened to 5 days (see protective vaccination). 



The clinical picture of rabies is on the whole the same 

 in the various species of animals, and the only variations 

 observed are owing to the fact tbat the symptoms are more 

 or less subject to modifications in accordance with the individual 

 temperament and the physical structure- of the animal. 



Rabies in Dogs. At the initial stage of the disease (stadium 

 prodrome rum or melancholicum), the animals show a peculiar 

 fchange in behavior, which, particularly in house dogs and with 

 the so-called "dumb rabies," is so inconspicuous that it is 

 completely overlooked, and the owners associate with them as 

 usual without suspecting anything. Most dogs become capri- 

 cious; they are at times irritable and gloomy, and avoid all 

 noise, hiding in dark places under or behind furniture, in a 

 dark corner of the room, or in the stable. They obey the call 

 of their master very unwillingly, but then jump about and fawn 

 on him even more markedly than usual. In other cases they 

 show a remarkable uneasiness, scratch with the fore feet, fre- 

 quently change their place of rest, walking uneasily around in 

 the yard or in the room, suddenly stopping, becoming attentive, 

 and without any cause barking and biting at the air (so called 

 "fly-catching"). If resting on the ground, they frequently 

 become startled and attempt to catch imaginary flies, growling 

 at the same time. 



The reflex excitability is in this stage already decidedly 

 increased. This is shown by the fact that the animals when 

 approached in, a friendly way, and still more when teased, 

 become excited and snap at the caressing hand and any other 

 objects or their companions. This excitability is particularly 

 conspicuous toward strange persons and dogs, even when they 

 are still friendly and familiar with their habitual attendants. 

 The reflex excitability is still more noticeable in that the pa- 

 tients become startled or jump up frightened even on slight 

 external causes, such as a strong light, sudden noises, touching 

 of the body, etc. During such paroxysms there are also ob- 

 served sudden but very transitory respiratory disturbances, 

 spasm of the diaphragm and dilatation of the pupils. Many 

 dogs scratch and gnaw or bite at the place of infection or the 

 cicatrix formed there. 



