396 MEaEiMS. 



to diagnose, it being nothing more than what in medical 

 language we should designate Yertigo." * 



Megrims is a disease common to old horses ; it is rarely 

 that young horses are so affected. Sometimes it appears in a 

 very mild form, and the attacks of Vertigo are manifested at 

 long intervals ; while in other cases they are so violent and so 

 frequent, especially when the horse is at work, as to render the 

 animal all but useless. 



Symptoms. — The attack is generally sudden. The animal 

 may be going at full trot, when all at once he will commence 

 shaking his head ; the ears will be drawn, in a peculiar manner, 

 close to the poll ; the eyelids quiver ; the nose will be pro- 

 truded, and the head will be pulled round to one side ; at the 

 same time the body of the animal will tend in the same 

 direction. If the driver perceives what is the matter, and pulls 

 the animal to a stand, further consequences, in all probability, 

 will be prevented ; but if he be ignorant of the affection, and 

 perseveres in driving forwards, or in driving quick, the attack 

 will be aggravated ; the animal will commence trembling vio- 

 lently, to breathe quickly, and to perspire ; he will rush 

 forward, unconscious of surrounding objects, stagger, and falj 

 to the ground, where he may lie for ten or fifteen minutes — at 

 the end of which time he will rise upon his feet, shake himself' 

 and proceed forwards as if nothing had happened. 



PATHOGFOMOifio SYMPTOMS. — TJie attack is sudden, and 

 the animal is affected ivith giddiness. 



Causes. — The disease may arise from the presence of 

 tumours within the ventricles of the brain ; also in conse- 



* Percival's " Hippopatliology," vol. iii., p. 27, 1st edition. 



