192 THEORY AND PRACTICE 



often the right hind quarter. A rather plausible theory has re- 

 cently been advanced that the disease is due to autointoxication 

 by the product of fermentation of the mass of food in the colon. 

 The disease develops only in heavy feeders and during idleness 

 the bowels get torpid, giving the ingesta ample opportunity to 

 ferment, producing some subtle poison that does the mischief. 



Post Mortem. — Where death sets in soon after congestion, 

 we shall find the muscles, particularly the affected ones, darker 

 colored than normal. The heart is filled with black clots of 

 blood; the kidney and liver are soft and the kidneys may be 

 gangrenous. There may be abscesses in the kidneys. The cere- 

 bral meninges will be more or less congested with some effusion 

 in the arachnoid space. The animal will be fat on the inside 

 even if lean on the outside. If the blood is plethoric, the animal 

 does not need to be fat in order to be predisposed to this disease. 

 Animals that are hard worked usually get an abundance of oats 

 and they are the ones most apt to take the disease though the 

 work may keep down the fat. 



Semeio'logy. — When the horse is taken out after a period of 

 idleness he feels good and dances around full of life. The dis- 

 tance he will then be able to go depends upon the amount of ni- 

 trogen set free by the muscular exertion. He may go one- 

 fourth of a mile, he may go twenty miles, but he soon begins to 

 sweat and blow. The blowing is due to congestion of the lungs, 

 the sweating to congestion of the skin. He begins to look 

 around, has an anxious countenance and gets lame in the hind 

 quarter. The fetlock knuckles — that is the first symptom of the 

 paralysis. The affected leg drags, he cannot bear any weight on 

 it, then the other fetlock knuckles and that leg becomes helpless 

 and all at once the horse is down. During this time the muscles 

 of the back often swell hard as a board. The horse lies quiet for 

 a time but colicky pains come on, he gets restless, the nerves 

 become intensely excited, pulse tumultuous, weak, uneven, and 

 finally dicrotic, and there is a convulsive motion of the limb. In 

 the early stage you will not find any abnormal condition of the 

 urine, but within an hour or two you will find it thick, and a 

 dark coffee color. The color is due to the pigment set free from 

 the blood ; the thickness is due to mucous. Sometimes it is so 



