24 DISEASES OP THE HOESE. 



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 when 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 



