484 Rabies. 



If no reliable history of the case is available or if it has only 

 been possible to have the animal under observation for a short 

 time, the diagnosis may present considerable difficulty. From a 

 practical point of view every animal in which a sudden change 

 of conduct is observed should be considered as suspicious and 

 only declared unaffected when for 3 to 4 days no symptoms 

 appear to confirm the suspicion. 



Differential Diagnosis. Diseases more or less similar to 

 rabies are observed, especially in dogs, and they may cause con- 

 fusion, particularly if symptoms of nervous excitement are pres- 

 ent. Thus, a violent irritability, sometimes connected with 

 aggressive conduct and a desire to bite, may appear as a result 

 of acute inflammatory processes of the meninges and the cere- 

 bral substance. Here belongs the acute cerebral hyperemia as 

 well as acute meningitis and encephalitis without regard to 

 whether these diseases occur from unknown causes or outside 

 influences, or are caused by animal parasites or tumors existing 

 in the brain. In such instances the further course of the disease 

 will decide, as cases of paralysis in other diseases are not devel- 

 oped in the same sequence and uniformity as in rabies. Eclamp- 

 sia and epilepsy are characterized by clonic spasms all over the 

 body while in epilepsy there is also the clear conciousness be- 

 tween the attacks. Nervous distemper is characterized by the 

 simultaneous symptoms in the eyes and respiratory organs, as 

 well as by distemper exanthema. 



Eepeated or continuous pains in some parts of the body 

 may irritate the animal to a degree which will cause attacks of 

 frenzy or delirium that are sometimes confounded with rabies. 

 To these belong the acute inflammation of the intestines caused 

 by intestinal worms, particularly tenia echinococeus, foreign 

 bodies, poisoning, perforation of the intestines, as well as many 

 cases of colic with violent symptoms in horses; further, dog 

 diseases caused by pentastomum tenioides, eustrongylus gigas, 

 and spiroptera sanguinolenta, and finally dermanyssus mites 

 in the external auditory canal of cattle, scabies mites in the ears 

 of dogs, as well as muscular rheumatism. In the course of these 

 diseases no paralysis appears, but the clinical aspects of the 

 disease may, owing to the exhaustion and comatose condition 

 on approaching death, be very similar to rabies sometimes to a 

 degree that makes an autopsy necessary to determine the real 

 nature of the disease. 



After lodgement of foreign bodies in the pharynx or 

 between the teeth of dogs and cats, rabies may be suspected, 

 because the animals show restlessness, and, owing to difficulty 

 in swallowing and to stomatitis, saliva is abundant and the voice 

 is hoarse from the perilaryngeal edema. On account of difficulty 

 in moving the lower jaw the mouth is kept continuously open, 

 which condition is very similar to the paralysis of the masseter 

 muscles. In such cases, as well as in the apparent paralysifj 



