294 



Sturdy or Gid in Sheep. 



[AUG., 



The disease known commonly under the names of sturdy, 



gid, turnsick, &c, is caused by the presence of a cyst, called 



Caznurus Cerebralis, in the nerve centres, 



Sturdy or Gid anc j more particularly in the brain. It is 

 m Sheep. , , ' % . ' , 



observed most frequently in lambs and 



shearlings, and more rarely in sheep over two years of age. 

 The disease occurs occasionally in goats, oxen, and other 

 ruminants. It is very rarely found in horses. 



The disease is due to the Taenia Ccenurus, or tape-worm of 

 the dog. This parasite lives in the small intestine and is com- 

 paratively common, especially in collie and other dogs in sheep- 

 rearing districts. When mature it may reach the length of 

 40 inches, and is made up of a square-shaped head with an 

 attenuated neck and a number of segments. These segments 

 contain eggs, and when ripe and ready to drop off are well- 

 marked objects, easily seen by the naked eye — about half an 

 inch long and one-fifth of an inch wide. When mature and 

 gorged with ova (which generally occurs in about two and 

 a-half months after the dog has become infected by eating the 

 cyst from the brain of an infected sheep), they are passed 

 through the bowel and reach the ground, probably in the 

 pastures where the sheep are feeding. They then decompose, 

 and the eggs are set free. The rain washes the eggs over the 

 grass, or into ditches or pools from which animals drink, and 

 these in their turn become infected. A certain amount of 

 moisture is requisite to maintain the vitality of these ova, as 

 it has been proved by experiment that a fortnight's exposure 

 to a dry atmosphere will destroy them entirely, whereas even 

 after three months' exposure on damp grass the eggs have 

 proved able to communicate the disease to lambs. Sturdy or 

 gid is more common, therefore, in flocks that feed in damp 

 pastures, or when the spring and summer have been rainy. 



Having reached the stomach of the sheep the egg hatches out 

 a six-hooked embryo which bores its way through the wall of 

 the stomach, enters a blood-vessel, and is eventually carried in 

 the blood to the brain, where it develops a cyst or bladder 

 which gradually increases in size and brings about the symptoms 

 characteristic of the disease. This cyst, which is the sole cause 

 of sturdy, is a vesicle of variable size, and, though originally 



