218 CLINICAL DIAGNOSTICS. 



B. Spinal Reflexes. 



1. Skin reflexes consist of muscular contractions fol- 

 lowing irritation of sensory peripheral nerves, e. g. manipu- 

 lation or percussion of the walls of the chest or the flank. 

 Touching the anus causes contraction of the sphincter ani 

 (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 

 tendon 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 cerebral anemia. Disturbance of consciousness, un- 

 steady gait, staggering, leaning against objects for support, neigh- 

 ing, shaking of head, falling. 



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 



