stomach (rumen) of gas. A thoroughly disinfected knife, or better 

 a trocar, should be used for this operation. All cases of bloat should 

 be treated at once. 



Prevention of Bloat. 



Sheep may be gradually accustomed to forage crops in a way 

 to prevent bloat. In the beginning, they should be well supplied with 

 grass or some dry roughage, and not placed on the forage until after 

 the dew is off. Allow them to graze for one hour the first day. Fol- 

 low this method on succeeding days, increasing the length of time by 

 an hour each day, and at the end of five days the sheep or lambs may 

 safely be placed permanently on the forage crop. It is good practice 

 to have blue grass pasture in addition to a forage pasture, for the best 

 use of the forage crop and the prevention of bloat. 



The Sheep Gadfly. 



Riley (1869) describes it as looking "something like an over- 

 grown house fly." It has no mouth and hence does not feed, the 

 principal purpose of the animal at this stage being that of reproduc- 

 tion. After the mating of the male and female flies, the female de- 

 posits its larvae, already hatched from the eggs, inside the nostril of 

 the sheep. The larvae are provided with hooks, and by means of 

 these they work their way up into the nostril of the sheep. The lar- 

 vae develop into grubs, which attain a length of three-fourths of an 

 inch (20 millimeters). The larvae are first white, but later become 

 yellow, and finally a dark yellow with a black band on each segment, 

 and the segments armed with black spines. This is the stage in which 

 the parasite is most commonly seen and described. At the proper 

 time the grub escapes from the nostrils, falls to the ground and bores 

 its way under the ground to a depth of one or two inches. After a 

 period, which varies with the weather conditions, the mature fly 

 emerges from its pupal case and makes its way to the open air. 



The larvae deposited by the female fly "crawl around in the 

 sheep's nostrils and work their way into the passages of the turbin- 

 ated bones and into the frontal sinuses." "The irritation caused by 

 the grub results in catarrh, from which the disease due to grub takes 

 the name of "snotty noses." Worse than this is the fact that the in- 

 flammation set up in the nasal mucosa causes an irritation of the nerves 

 of smell, and the inflammation is transmitted along the short course 

 of these nerves to the brain. When the grubs are numerous the ef- 

 fects on the sheep are serious and at times fatal. The catarrh is ac- 



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