THE HORSE, ITS DISEASES. 41 J 



is clear that congestion of the brain, perhaps of the venous system gen-^ 

 erally, is the condition that prevails when the disease manifests itself in 

 its active and violent stage. And this too great fullness of blood is iu 

 most cases owing to disordered digestion, which may be brought about in 

 two ways : the horse may be overfed and subjected to insufficient exer- 

 cise, so that the stomach becomes weak, and lacks the power to digest or 

 expel the food ; or he may suddenly gorge himself when chancing to 

 come upon abundance of food of which he can partake without restraint. 

 The fulness of the stomach and bowels produces that internal compres- 

 sion which precludes the regular flow of blood through the veins, and 

 weakens the venous system, and the brain soon becomes overcharged, 

 awd that, too, with a fluid in a degree poisonous for want of perfect oxy- 

 genation, or purification by being regularly passed through the lungs and 

 exposed to the air. Hot weather is peculiarly favorable to the attack, 

 both because of the more debilitated state of the system from heat, and 

 because the heat predisposes a more rapid arterial flow of blood, that is 

 not counterbalanced by an equally rapid return of the blood through the 

 veins to the heart and lungs. 



Luxuriant pasture, warm weather, and the dependent posture of the 

 animal's head in his continual cropping, especially if he is in over-condi- 

 tion and full of blood, may readily produce apoplexy — the immediate and 

 the remote cause in this case seeming to act simultaneously. Horses in 

 poor condition may be attacked after having been overworked and re- 

 duced to a debilitated state throua-h want of care and of nourishins: food. 

 Put upon rich pasture, with a ravenous appetite, they are apt to gorge 

 and bring on indigestion and its attendant constipation. 



There is sometimes a softening of the brain, rather than effusion or 

 too great fullness, and this may arise from tumors, caused by blows, or 

 by the plugging of the vessels with clots of fibrous matter. 



How to know it. — This differs from blind staggers or megrims in this, 

 at least, that the prevailing symptoms force themselves upon the atten- 

 tion of the ordinary observer while the horse is at rest. He exhibits at 

 first a want of appetite, and is more than usually dull. When he walks 

 his movements are slow and unsteady. Examination will discover his 

 pulse to be slow, heavy and dull, yet full. When he is exercised a little 

 these symptoms go off, but they soon return when he is left to himself, 

 and more unmistakably. In the open air he balances himself as though 

 about to fall, and stands with his head depressed. In the stall he bears 

 upou the trough or the wall, and a good deal of his weight seems to be 

 supported in this way. Sometimes he gets his head against some rest, 

 stands for a length of time, and then drops as though shot, but presently 

 gets upon his feet again, to relapse into the same sleepy listlessness. 



