CESTRUS LARV.*: IN THE FACIAL SINUSES OF SHEEP. 



331 



Death may occur during such attacks, which, however, are happily 

 very rare. Most commonly the animals are simply dull and somnolent. 

 They feed badly, carry their heads low, and sometimes hide themselves 

 under the mangers or in corners. 



In exceptional circumstances they bury their heads in the wool or 

 carry them high in the air in walking, while they lift their front legs 

 high, with a stepping movement. 



Diagnosis. The diagnosis of parasitic invasion of the sinus in the 



Fig. 169. — Parasitic invasion of the sinuses and coenurosis (showing the 

 seat of operation in either condition). 



sheep is rather difficult, because certain of the symptoms suggest gid. 

 One never finds the signs of true gid, however, and, on the other hand, a 

 certain amount of discharge and attacks of snorting always exist. Finally, 

 gid (coenurosis) only attacks young animals, whilst the larvae of oestridae 

 are commonest in adults. 



To confound the disease with verminous bronchitis is still less likely, 

 for although a discharge exists in both cases, this is accompanied by 

 cough in bronchitis, and only by sneezing attacks in infection of the 

 sinuses. 



