NERVOUS SYSTEM. 201 



1. All acute infectious diseases ; contagious pleuropneu- 

 monia, influenza, Rinderpest, anthrax, horse, distemper, dog 

 -distemper, septicemia, Rothlauf of swine, etc. 



2. All severe febrile diseases. 



3. Chronic affections of the brain : blind staggers, turn- 

 sick of sheep, second stage of acute cerebritis and cerebral 

 hyperemia. 



4. Poisoning with narcotics. 



5. Icterus, uraemia. 



C). Chronic gastric and intestinal affections of the horse. 



Dizziness (vertigo) and syncope (fainting) are sud- 

 denly occurring t e m p o r a r y disturbances of conscious- 

 ness and loss of equilibrium. Animals suddenly become un- 

 steady in gait or standing position, sway, reel, stagger and 

 sometimes fall to the ground. The cause may consist of the 

 presence of parasites in the brain, hemorrhages, tumors, ab- 

 scesses, passive cerebral hyperemia (compression of jugulars 

 by harness), aortic insufficiency or stenosis, also the action 

 of glaring light ("ocular vertigo"), irritations of the external 

 auditory meatus, and of the nasal mucous membrane by para- 

 sites, finally also of poisoning with certain plants. 



II. Sensibility. 



The sensibility is tested by artificial stimulation, sticking 

 :a finger into the ear, flipping the nose with the finger, stepping 

 on the coronet, pin pricks. In testing the general sensibility 

 observe that no inflammatory condition exists in the part 

 "tested." Peripheral irritation may give rise to spinal reflex 

 actions, e. g. the hoof may be raised without any conscious- 

 ness of the act on part of the animal either as to the act or 

 stimulus producing it. For this reason the gen- 

 eral behavior of the whole animal must 

 be taken into account in testing its 

 sensibility. If dogs cry out during such an examination, 

 ■or test we may conclude that conscious feeling exists. 



