NERVOUS SYSTEM. 207 



(anal reflex) ; touching the skin at the perineum results in 

 drawing up of the tail and depression of the croup. 



2. Mucous membrane reflexes. Pressure upon the 

 larynx or the upper rings of the trachea produces a cough 

 (laryngeal reflex). 



3. Tendon reflexes. Striking the flexor tendons of 

 the carpus, the inferior patellar ligaments or the achilles ten- 

 don causes the animal to raise its legs. 



4. Normal defecation and urination. 



Spinal reflexes are diminished or absent in disturbances 

 of the reflex arc, hence in peripheral paralyses and diseases 

 of the spinal cord. Increased reflexes are observed in hyper- 

 esthesia, strychnine poisoning and in diseases of the reflex 

 inhibitory centers of the brain. 



Diseases of the Nervous System. 



Cerebral congestion. Hyperemia of short duration, fluctuat- 

 ing in character and entirely curable. Begins with stage of ex- 

 citement; animals are restless, try to force themselves forward or 

 sideways, rear, kick, shake their heads, walk backwards, tear the 

 halter strap, etc. After a few hours the stage of depression sets 

 in: animals are stupefied, sad look of the eye, head down, disregard 

 familiar commands. 



Acute inflammation of the brain, acute hydrocephalus. Differs 

 from congestion in its more pronounced symptoms and its longer 

 duration. In the second stage (that of depression) we observe 

 abnormal attitudes and movements, staggering, sometimes falling 

 down and inability to get up again, sometimes attacks of raving 

 madness. Temperature frequently increased, but fever may be 

 absent. Feeding always more or less interrupted, especially the 

 manner of feeding. 



Blind staggers. Morosis equorum. Hydrocephalus chronicus. 

 This is a chronic apyretic incurable affection of the cerebrum which 

 manifests itself by mental disturbances, and by impaired locomo- 

 tion and sensibility. Pulse strong and full, number of heart beats 

 never increased, but frequently diminished — a very constant symp- 

 tom. Appetite usually good but animal eats slowly. Ability 

 to work present to a limited degree. Examination for staggers. 

 See p. 180. 



Epilepsy, "Falling sickness" is a chronic disease of the brain 

 characterized by paroxysms occurring at intervals and attended 

 by sudden loss of consciousness and disturbed sensibility. 



Dizziness, vertigo. This is a primary disease,' occurring at 



