DISEASES OF TILE BRAIN AND NERVOUS SYSTEM. 76 
to the exercise taken. The fear of punishment, especially of the 
wlip, occasionally gives rise to it, in sensitive and irritable ani 
mals. Some horses have an hereditary predisposition to it, and 
mares are considered more subject to it than stallions. Further, 
it is scarcely ever observed except in hot weather; and as it ia 
gencrally at the beginning of summer that it commences to appear, 
it goes away always in autumn, at least with respect to its chief 
4y mptoms. 
Symptoms.—The horse having, previous to the attack, been 
sively and active, begins, all of a sudden, to appear heavy and in- 
dolent. He is dejected, and prefers to keep himself in the dark- 
est corner of the stable. Eyes, dull; look, fixed and stupid; eye- 
lids, half shut ; inattention to every thing, forgetting even himself, 
and, as it were, asleep, his head hanging down, or resting on the 
manger. His gait is heavy, slow, and unsteady ; he raises his feet 
very high, and puts the entire sole to the ground, raising and let- 
ting down the limbs in a manner purely mechanical, and, as it 
were, unconsciously. He exhibits much awkwardness in turning, 
and can not be pulled back except by depressing the head very 
much, and pushing it latterly. He also leans to one side in walking, 
To maintain his equilibrium the better, he places the fore-legs 
beneath the belly, and moves his ears backward in a peculiar 
manner. According as the disease progresses, he becomes less 
and less sensible to external impressions. Mastication is per- 
formed slowly. He takes, from time to time, a mouthful of food, 
masticates it, swallows a portion of it, but keeps the remainder 
in his mouth. He prefers taking his fuod off the ground rather 
than in any other way, and when drinking, he plunges his head 
into the water, even above his nostrils. During and after some 
rather violent movements, his symptoms become much aggra- 
vated, and the signs of complete insensibility become more and 
more marked. The animal runs on quite blind till some obstacle 
stops him, or turns round, or remains tranquil, with his head 
depressed, and the legs crowded beneath the body, without being 
able to change this unusual attitude, unless assisted to do so, 
There is never any fever. The pulse is often from ten to twelva 
pt.sations slower than in the normal state. 
In the same way, also, the respiration is constantly slow, 
deep, and frequently of a sighing character. In almost all cases, 
the tongue is foul, and the mouth dry an1clammy. With respect 
