520 DISEASES AND THEIR TREATMENT. s 



DISEASES OP THE NERVOUS SYSTEM. 



The nervous system consists of the brain, which is lodged in the 

 cavity of the skull (cranium) ; the spinal cord, lodged in the cavity 

 of the vertebral chain; and numerous little white cords, called 

 nerves, which are given out from the brain and spinal cord, and dis- 

 tributed to the different parts of the body, especially those parts 

 endowed with sensibility, and under the control of the will. Besides 

 this system of nerves, there is another set, independent of the cere- 

 bro-spinal axis, called the sympathetic or ganglionic system, which 

 supplies the organs of nutrition and other viscera, blood-vessels, etc. 

 It consists of numerous striall centers, called ganglia, extending in 

 two great chains from the head to the tail, on each side of the bodies 

 of the vertebrae, closely associated with the other system by intri- 

 cate communication. 



Inflammation of the Brain (Phrenitis). 



Phrenitis is not a very common disease, though the substance 



of the brain itself, or, as is more 

 commonly the case, its membranes, 

 or coverings, become inflamed. It 

 has received various appellations, 

 such as mad staggers, sleepy stag- 

 gers, etc. i 



Causes. — The causes are hot 

 thoroughly understood.! Injuries 

 to the skull, metastasis, or the 

 transference of inflammation from 

 some of the other organs, high 



„ „ K „ _ condition and overwork, undue ex- 



Fio. 837.— Symptom of Inflammation , 



of the Brain. "* P osure to a hot sun, all seem to 



be favorable to its production. 

 Horses that are too highly fed are subject to this, while moderately 

 fed horses are scarcely ever inclined to it. 



Symptoms.— It is usually ushered in by dullness and persistent 

 drowsiness ; he stands with his head between his legs, or sometimes 

 resting against the manger or leaning against the wall ; the eyes 

 shut, and the pupils dilated; the pulse is full, soft, and slow; the 

 breathing is heavy and loud ; he is very difficult to arouse, and When 

 startled, he looks dreamily about ; may ]take a few bites of hay, but 

 soon drops asleep again; the bowels are costive, And the urine 

 scanty and high colored. 



In a day or two the symptoms are mitigated, or it goes on to 



