568 NERVOUS DISEASES. 



will bury hia mouth, in the water he wishes to drink. Note here 

 that the horse performs the act of drinking by using his mouth as 

 a suction pump; the diminution in the pressure of the air con- 

 tained in the mouth being made by drawing back the tongue. 

 Hence, in order for this pump to act properly, the lips must be 

 firmly closed together above their point of immersion in tne fluid. 

 When paralysis of the lips exists, the animal is obliged to bury his 

 muzzle above the corners of his lips in the fluid, so that fluid, not 

 air, may enter his mouth. 



CAUSES. — As the course of these nerves, from ear to lips, lies 

 almost immediately underneath the skin, they are particularly 

 liable to external injury from blows, use of heavy and ill-fitting 

 bridles, pressure on the head while the animal is held on the 

 ground during operations, and similar causes. In their deeper 

 portions they may suffer from pressure caused by tumours, enlarged 

 glands, inflammatory exudations, or extravasated blood. Conse- 

 quently, this paralysis sometimes follows influenza and other 

 diseases. A fall or severe blow on the head might damage their 

 point of origin in the brain. 



CHANCES OF RECOVERY.— The liopeful cases are those of 

 recent standing and when paralysis is confined to the lips and 

 nostrils. 



TREATMENT consists in removal of pressure from the part ; 

 warm fomentations ; and subsequently, biniodide of mercury 

 blisters (p. 632) below the root of the ear, and, partly, down the 

 cheek ; a dose of aloes ; and soft and laxative food, placed in a 

 bucket, so that the animal may easily eat it. Half an ounce of 

 iodide of potassium may be given daily in the drinking water, or 

 in a mash. The action of this salt is to cause absorption of any 

 exudation which may result from inflammation, and which may 

 be the outcome of pressure on the nerves of the part. 



Megrims, Staggers and Epilepsy. 



The affection called in stable language, megrims, or staggers 

 somewhat resembles apoplexy in its mode of invasion, and may 

 be due to many causes, among which, pressure of the collar, in 

 giving rise to congestion of the brain, appears to be the chief. 

 There is the certainty that animals which have been subject to 

 attacks of megrims when working in the ordinary collars have 

 enjoyed perfect immunity from such seizures, when worked with a 

 strap or band across the breast. This is a fact recognised not in 



