24 : DISEASES OF THE HORSE, 
irresponsive to external stimuli. Cerebral depression also occurs in 
the severe febrile infectious diseases, in chronic hydrocephalus, in 
chronic diseases of the liver, in poisoning with a narcotic substance, 
and with chronic catarrh of the stomach and intestines. 
Fainting is a symptom that is not often seen in horses. When it 
occurs it is shown by unsteadiness of gait, tottering, and, finally, in- 
ability to stand. The cause usually lies in a defect of the small brain, 
or cerebellum. This defect may be merely in respect of the blood 
supply, to congestion, or to anemia, and in this case it is likely to pass 
away and may never return, or it may be due to some permanent 
cause, as a tumor or an abscess, or it may result from a hemorrhage, 
from a defect of the valves of the heart, or from poisoning. 
Loss of consciousness is known as coma. It is caused by hemor- 
rhage in the brain, by profound exhaustion, or may result from a 
saturation of the system with the poison of some disease. Coma may 
follow upon cerebral depression, which occurs as a secondary state 
of inflammation of the brain. 
Where the sensibility of a part is increased the condition is known 
as hyperesthesia, and where it is lost—that is, where there is no feel- 
ing or knowledge of pain—the condition is known as anesthesia. The 
former usually accompanies some chronic disease of the spinal cord 
or the earlier stages of irritation of a nerve trunk. Hyperesthesia is 
difficult to detect in a nervous, irritable animal, and sometimes even 
in a horse of less sensitive temperament. An irritable, sensitive spot 
may be found surrounded by skin that is not sensitive to pressure. 
This is sometimes a symptom of beginning of inflammation of the 
brain. Anesthesia occurs in connection with cerebral and spinal 
paralysis, section of a nerve trunk leading to a part, in severe mental 
‘depression, and in narcotic poisoning. 
URINARY AND SEXUAL ORGANS. 
In considering the examination of the urinary and sexual organs 
we may consider, at the beginning, a false impression that prevails to 
an astonishing extent. Many horsemen are in the habit of pressing 
upon the back of a horse over the loins or of sliding the ends of the 
fingers along on either side of the median line of this region. If the 
horse depresses his back it is at once said “his kidneys are weak.” 
Nothing could be more absurd or further from the truth. Any 
healthy horse—any horse with normal sensation and with a normally 
flexible back—will cause it to sink whén manipulated in this way. If 
the kidneys are inflamed and sensitive, the back is held more rigidly 
and is not depressed under this pressure. 
To examine the kidneys by pressure the pressure should be brought 
to bear over these organs. The kidneys lie beneath the ends of the 
