126 THE PRACTICE OF VETERINARY MEDICINE. 



Over-ripe grasses will produce it, as will decomposing roots, 

 as, for instance, where the roots lie in a ceHar all winter 

 and are fed to the stock in the spring of the year. The 

 disease may also occur as a result of eating weeds or plants 

 possessing narcotic properties. In Great Britain horses, at 

 certain seasons of the year, are fed on rye-grasses, and in 

 consequence brain diseases are very common where the rye- 

 grass is over-ripe and taken in excessive quantities. Buck- 

 Avheat will also produce it, as will mouldy or bad food of 

 any kind, especially if given for any length of time or in 

 large quantities. Tumours or abscesses forming in the brain, 

 as a result of irregular strangles, melanotic deposits, etc., 

 also operate as causes of encephalitis. 



Symptoms. — The symptoms vary to a considerable extent. 

 In most cases there is marked dulness, w^iich generally 

 increases as the disease progresses- The animal assumes a 

 dull, listless attitude, but is easily excited by a little noise, 

 after which he soon relapses into his former dull, sleepy 

 mood. The urine is scant in cpiantity ; the bowels are con- 

 stipated ; the respirations slow, and usually stertorous in 

 character. As a rule, the pulsations are fewer in number 

 than in health, sometimes running down to thirty, or even 

 as low as twenty-six beats per minute. In other cases, in 

 addition to the dulness above described, the animal has 

 occasional convulsions, manifested by slight trismus and the 

 projection of the membrana nictitans. 'Some cases have 

 come under my observation that, during the early stages, I 

 thought were going to be well-marked cases of tetanus ' 

 {Smith). When standing quietly in the box, he shows a strong 

 inclination to rest his head against the wall or the manger. 

 In other cases, the breathing becomes stertorous, the pulse 

 becomes accelerated, the eyes bloodshot, and the poor 

 animal, in a state of frenzy, will knock himself about in the 

 most violent manner, and without the least regard for the 



