154 VETERINARY STUDIES 



some cases accompanied by wheezing. Calves are able to resist 

 rather longer than sheep. 



On examination post mortem there may be found masses of 

 minute threadlike worms in the trachea and bronchial tubes, 

 with a considerable quantity of purulent and viscid liquid in 

 the tubes. Some lobules of the lungs may show very marked 

 pneumonia. There may also be tubercles resembling those of 

 tuberculosis, near the surface of the lungs, and also throughout 

 the lung substance. 



Treatment.— Treatment by injection of medicines directly 

 into the trachea has been tried and recommended in some cases, 

 but is very apt to prove unsatisfactory. 



Benzine has been tried and reported successful. Inject about 

 one dram (1 teaspoonful) slowly into the trachea. Use an 

 ordinary hypodermic syringe and inject directly through the 

 side of the trachea between two rings. The sheep must be held 

 flat on the side at the time of injection and for five minutes 

 afterward with the head as low as possible. It would be wise 

 to treat but a few sheep at first and note results. 



The most promising treatment at present is by chloroform. 

 Inject one-half to three-fourths of a teaspoonful of chloroform 

 into the nostrils with an ordinary medicine dropper. Hold the 

 head up and close the nostrils for a while. It would be well to 

 begin this treatment cautiously. 



This treatment should be repeated two or three times at inter- 

 vals of three to five days. Calves should have the same treat- 

 ment with proportionately larger doses. 



Prevention. — Change pastures often ; keep sheep upon forage 

 crops and upon frequently changed pastures. Avoid ponds, and 

 well water which receives drainage from pastures, feed lots or 

 barn yards. 



Nasal Grub — Sheep (Grub in the Head) 



This is a very poor name for a disease, but is the only one 

 commonly understood, and is used here for that reason. 



Cause. — This disease is caused by the larva? of a fly {Oestrus 

 ovis). This larva inhabits the various cavities of the head which 

 communicate with the nasal chambers. See figure 52. 



Life history. — The mature fly resembles the well known bot 

 fly of the horse, is of a dirty yellow or grayish yellow color, and 



