DISEASES OF THE BRAIN. 479 ' 



fitting collars. True megrims occurs most readily in ani- 

 mals with obstructed jugular veins, from previous attacks 

 of phlebitis, but such obstructions are rare now-a-days in 

 this country. 



The symptoms of vertigo or megrims come on suddenly, 

 and often unexpectedly, so that accidents, especially in 

 hilly districts, of a serious nature, often befal the persons 

 driving horses thus attacked. The animal seized, elevates 

 the head, has twitchings of the neck ; sometimes the spasms 

 attack the muscles on the one side, or all the superior 

 cervical muscles are contracted, and owing to the peculiarly 

 prominent eyeballs and wild look of the animal upwards, 

 it has been called, when subject to these attacks, a " star 

 gazer." The muscular twitchings of the face, turgid condi- 

 tion of the veins of the head, and dilated nostrils, are also 

 marked, and with a sudden bound the animal falls against 

 any obstruction or into any chasm without perceiving its 

 danger. In fact the pupils are dilated and vision suspended 

 during the next severe period of the paroxysm ; the reeling, 

 delirium, or stupor ceases, and vision is suddenly restored 

 on the circulation being re-established. Such attacks have 

 been wrongly attributed to inflammation, phrenitis; and 

 grooms or farriers, not excepting even veterinary surgeons, 

 are ready to jag the mouth in order to draw blood, or to 

 bleed from any accessible artery or vein. 



It will be usually found that an animal thus seized is 

 being driven with a tight collar, or though the collar may 

 appear deep enough when the animal holds its head down, 

 it presses on the lower part of the jugular veins as the head 

 is elevated in action, and especially in drawing a load up a 

 hilL The way to relieve is therefore to push the collar 

 forward, and if water be at hand, to pour some on the head. 



Horses addicted to megrims have been driven with a 



