50Z MANUAL OF .MODERN FARRIERY. 



skull and brain, and even sometimes in the ventricles of tlie 

 brain. 



The first symptom which manifests itself, is the sheep 

 lagging behind its companions in the pasture ground, and 

 assuming a dull, sluggish appearance. Then the animal 

 will be noticed to go round, as if giddy ; its eyes look as if 

 they were blind; and ultimately he dies. But all these 

 symptoms may be apparent for a considerable time before 

 death ensues. Sheep labouring under this complaint often 

 feed well to the last, and die in good condition. 



Causes. — One form of this disease proceeds from an over- 

 abundant supply of that fluid which moistens the ventricles 

 of the brain. This is considered incurable. Tlie more 

 common state proceeds from a species of worms, called 

 hydatids. These animals are formed like bags or cysts, 

 and are filled with a fluid. They do not inhabit the sub- 

 stance of the brain, but lodge between it and the skull. It 

 is by the pressure of those cysts that this malady is pro- 

 duced, and which generallj terminates fatally, and the brain 

 becoming diseased from being subjected to a long continu- 

 ance of that pressure. 



Eemedies. — The celebrated poet, Hogg, better known by 

 the name of the Ettrick Shepherd, discovered one mode of 

 curing the species of disease which is caused by hydatids. His 

 plan was to thrust a knitting-needle up the nostril of the ani- 

 mal and force it through the skull, into the cyst, which destroy- 

 ed the hydatid, and the sheep then recovered its usual health. 



In cases where a portion of the skull becomes soft, it is 

 penetrated by a common awl, which permits the water to 

 escape, and a cure is effected. Care must be taken not to 

 pierce the substance of the brain by forcing the awl too 

 deep. Trepanning has been recommended, and successfully 

 performed by some veterinary surgeons. It is, however, too 



