DISEASES OF THE NERVOUS SYSTEM 113 



The causes of congestion of the brain are faulty methods of 

 care and feeding. It sometimes occurs when horses are shipped 

 in poorly ventilated cars, or kept in close stables. Climatic 

 changes, or changing the stable and feed, may cause it. Ex- 

 tremely fat animals and animals that are rapidly putting on fat 

 are predisposed to this disorder. Improper methods of feeding, 

 lack of exercise, constipation and excitement are the most com- 

 mon causes. Passive congestion may result from pressure on 

 the jugular vein by obstructing the flow of blood from the brain, 

 and raising blood pressure in the blood-vessels of the brain. It 

 is sometimes caused by organic heart trouble. 



The symptoms come on very suddenly in congestion of the 

 brain. The disease may manifest itself as soon as the animal 

 is moved out of the stall or bed, or it may come on while it is 

 feeding. In slight cases, the animal appears excited and rest- 

 less, the eyes are bright, the pupils are dilated, and the pulse 

 beats and respirations quickened. If the animal is moving 

 about, it may stop suddenly and show marked symptoms of a 

 nervous disorder, such as turning around, running straight ahead 

 and falling down. The period of excitement is usually brief and 

 may be followed by marked depression. The mucous membranes 

 of the head are a deep, red color. 



The symptoms in amx-mic conditions of the brain are loss of 

 consciousness, stumbling, falling to the ground and sometimes 

 convulsions. The pig and dog may vomit. Favorable cases 

 return to the normal within a few hours. Acute inflammatory 

 diseases of the brain and its coverings are associated with cere- 

 bral hypera?mia or congestion. 



The treatment of mild cases is to give the animal quiet, 

 well-ventilated quarters, where it can not injure itself. The 

 animal should be first subjected to a severe diet and later given 

 easily-digested feed. If it appears greatly excited, bleeding 

 should be practised. Cold applications to the head should be 

 used in all cases in the small animals. For internal treatment, 

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