GENERAL ACCOUNT OF THE SHEEP. 121 



veterinarian is called upon to treat sheep individually, for only 

 in the case of valuable breeding ewes or rams is it usually sup- 

 posed to be worth while to do so. Asa rule his advice is sought 

 when a whole flock of sheep goes wrong, as frequently is the 

 case. Sometimes a flock of sheep may suffer from verminous 

 bronchitis, or they may be severely afflicted (especially lambs 

 and young sheep) with intestinal tapeworms, and sometimes with 

 divers other kinds of evils, e. g. those incident to ewes before 

 or at the lambing season, and so forth. The gadfly of the sheep 

 the CBstrus ovis, is the source of terrible distress and torment. 



That the sheep is liable to the attack of this fly, which deposits 

 its eggs in the nostrils of the unfortunate animal attacked, was 

 as well known in ancient as in modern times. Instinctively aware 

 of the presence of this insidious and dreaded enemy, the sheep 

 display the greatest terror at the sharp and menacing sound pro- 

 duced by the gadfly's wings as the insect sweeps through the air. 

 They congregate together, placing their heads almost in contact 

 with each other, snort, and paw the ground, and use all means in 

 their power to prevent the fly from accomplishing its fell pur- 

 pose. When a gadfly succeeds in attaining its aim, it rapidly 

 deposits an egg or two in the nostril, and then leaves them there. 

 The eggs are soon hatched, and the young larvse crawl up the 

 nostril towards the frontal sinus. There they remain until full 

 grown, when they crawl through the nostrils, fall on the ground, 

 burrow therein, and undergo their changes into the pupal and 

 perfect stages. 



Again, sheep-scab is a far more important disease in the case 

 of the sheep than is scabies in other animals, on account of the 

 damage it does to the fleece. When we come to the consideration 

 of braxy, a name given to different diseases of sheep, one of 

 which is anthrax, we shall have to point out that the carcases of 

 sheep which have been afflicted with this latter malady should 

 never be used for human food. Further, when we come to 

 small-pox of sheep, we shall find that '* the resemblance of this 

 disease to human small-pox is very remarkable, both in symp- 

 toms, mode of communication, and rate of mortality " (Dr. 

 Gregory) ; and also that it sheds some valuable light on the 

 relations of that disease. 



In nearly all cases of disease in sheep, both remedial and pre- 

 ventive measures have to be undertaken on a large scale. Some 



