DISEASES OF THE BRAIN AND A'EKVOUS SYSTEM. 109 



of the brain, but the nature of the disease is not well understood. By 

 some veterinarians it has been defined to be a momentary and i:)assing 

 congestion of the brain. 



Etiology. — High feeding with occasional overwork. Collars which 

 fit badly and press on the veins which convey the blood from the head. 

 Intervals of overstrain on hot muggy days, and tight checking up, seem 

 somehow to have an influence in producing it. Indigestion and consti- 

 pation, worms and hereditary tendency are among the causes of megrims. 



Symptoms. — The attack is very sudden and peculiar. There are 

 seldom any premonitory symptoms. The animal suddenly shakes and 

 throws up his head, or shakes it violently or reels and then stands for a 

 minute or two dull and listless, or runs round, and falls to the ground, 

 remaining for a few moments partially insensible or in a state of violent 

 convulsion. The attack rapidly passes away, the horse rises in a minute 

 or two, shakes himself and proceeds as if nothing had happened, though 

 perhaps he may appear somewhat debilitated. During the fit his urine 

 or dung may escape from him involuntarily. The attacks are usually 

 periodical, and occur chiefly during hot weather and at severe harness 

 work. 



There is seldom any outward sign which indicates liability to this 

 disease. On the contrary, the horse generally looks well, has a good 

 appetite, and shows no special nervousness or dulness. 



Treatment. — If the attack comes on while driving, stop immediately 

 and loosen the check rein, the throat latch, and the collar. If after 

 standing a minute or so the excitement continues, take the harness all 

 off and pour cold water on his head. After the attack is over, lead the 

 horse home and put him into a loose box, feed him bran mashes and give 

 plenty of water to drink. A purgative will be of service. Take of 



Aloes 3 iv. to 3 vi. 



Ground ginger 3 i j. 



Molasses sufficient 



To form one ball. 



As a preventive, keep the animal in fair, not high condition, and in 

 regular work, with diet sujaiciently laxative to insure his bowels being 

 moderately open. 



An overloaded or deranged state of the bowels is apt to aflect injuri- 

 ously the functions of the brain. 



