1C3 PKESSUKE ON THE BRAIX. 



monest cases. The causes of most diseases are so obscure, their symptoms 

 so variable, and their connection with other maladies so complicated and 

 mysterious, that a life devoted to professional study will alone qualify a man 

 to become a judicious and successful practitioner on the diseases of the horse 

 and other domestic animals. Our object will be to communicate sufficient 

 instruction to the fai-mer to enable him to act with promptness and judg- 

 ment when he cannot obtain professional assistance, to qualify him to form 

 a satisfactory opinion of the skill of the veterinary surgeon whom he 

 may employ, and, more especially, to divest him of those strange and 

 absurd prejudices which in a variety of cases not only produce and prolong 

 disease, but bring it to a fatal termination. 



CONCUSSION OP THE BRAIN. 



This consists of a sudden interruption of the functions of the brain, 

 caused by some mechanical injury to the head, such as a fall or violent 

 blow, not necessarily accompanied by structural injury to the brain itself. 

 It is frequently produced by the horse rearing and falling backwards, 

 bringing the head with great violence to the ground, or by the animal 

 running away and the head coming in contact with a wall or some hard 

 substance. After the injury, the animal generally lies motionless and in- 

 sensible, and may continue so from a few minutes to half an hour. When 

 in this state, he should be allowed to remain for a time Avithout being dis- 

 turbed, and, in most cases, sensibility will quickly return. The animal 

 having risen, should be removed into a well ventilated but somewhat dark 

 stable. He should be kept for a few days perfectly quiet; a dose of pur- 

 gative medicine should be given, and his diet consist of soft foods, such as 

 bran- mash — when, if no other symptoms show themselves, he may be 

 considered convalescent. The most serious results which sometimes follow 

 this injury of the brain, are fracture of the bones of the skull, or ruptui'e 

 of some large vessel connected with the brain. 



PRESSURE ON THE BRAIN. 



Hydatids are ofien found within the cranial cavity, and l^'ing upon or 

 imbedded in the brain of oxen and sheep. Their existence is usually fatal 

 to the animal. There is no well-authenticated account of the existence 

 of an hydatid in the cranial cavity of the horse ; but cysts, containing 

 a serous or viscid fluid, are occasionally observed. The following is the 

 history of one : — A horse exhibited symptoms of vertigo, or staggers, 

 which disappeared after copious bleeding and purgatives. Aboiit twelve 

 months afterwards the same complaint was evident. He carried his head 

 low and inclined to the right side. He staggered as he walked, and the 

 motion of his limbs was marked by a peculiar action, confined to the fore 

 extremities. He moved by a succession of spasmodic boundings. He 

 was completely deaf; and rapidly lost flesh, although he ate and drank 

 voraciously. He remained in this state, to the shame of' the owner and 

 the practitioner, several months, and then he had a fresh attack of vertigo, 

 and died suddenly. On examination of the brain, its membranes were 

 found to be completely reddened ; and between the two lobes of the brain 

 was a round cyst as large as a pullet's egg. The pressure of this was the 

 manifest cause of the mischief. 



This may also be produced by some fluid thrown out between the mem- 

 branes, or occupying and distending the ventricles of the brain. In the 

 full-grown horse it rarely occurs ; but it is well known to breeders as an 

 occasional disease of the foal, under the name of ' water in the head ' — 

 hydi'ocephalus. The head is either much enlarged, or strangely deformed, 



