26 DISEASES OF THE NOSE AND ADJACENT SINUSES 



however, the sheep become quiet and remain so until the 

 emigration of the parasite begins. 



Symptoms. — If only one or two grubs are present, beyond a 

 slight liasal discharge, the sheep may show no symptoms. 

 When large numbers are in the head, however, the patients 

 show profuse mucopurulent or even bloody nasal discharge, 

 sneezing, snorting, sniffling, shaking the head and rubbing 

 the nose against objects. In severe cases symptoms of 

 vertigo occur, the patient staggering, reeling, and falling 

 to the ground. Sometimes fatal convulsions are noted. 

 Conjunctivitis may be present. As a rule, however, in 

 about ten days after the first signs appear, and the larvae 

 are expelled, the symptoms subside. 



Diagnosis. — Grub-in-the-head may be confused with sturdy 

 or gid (Ccenm-us cerebralis) . However, in sturdy the older 

 sheep are attacked, there are no nasal symptoms and the 

 forced movements of the patient are more pronounced. Gid 

 is furthermore as yet an uncommon disease in the United 

 States. In doubtful cases a postmortem or the micro- 

 scopic examination of the discharge must decide. 



From verminous bronchitis it may be distinguished 

 by the absence of the cough and rales on auscultation so 

 characteristic of bronchitis. 



Treatment. — ^Very unsatisfactory. Trephining the sinuses 

 and removing the larvae with forceps is only practicable in 

 isolated cases and among valuable sheep. Nasal douches 

 do not reach the larvae in the^ sinuses. In severe cases 

 slaughter is the most economical disposition. 



Prevention. — It is recommended to place in the pasture 

 field a log in which a number of 2-inch augur holes have 

 been bored. Salt is put in the bottom of each hole and 

 around the margin tar. When the sheep attempt to get the 

 salt the nostril becomes tar-smeared, wjiich partially, at 

 least, protects against the bot fly. Allowing the sheep 

 constant access to lime is of some value. Plowing a few 

 fm-rows in the pasture serves to furnish dust in which the 

 sheep may burrow their noses to avoid the fly. 



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