SOME PESTS OF OHIO SHEEP 



67 



small scale, using three of the ewes most heavily infested. On two 

 of these the powder was blown into the wool near the skin. On the 

 one, the powder was dusted over the surface of the wool. As so- 

 dium fluorid is a heavy salt it was thought the powder would settle 

 into the wool. A later examination showed that this method was 

 not effective. 



The trial test, however, proved satisfactory. So the entire 

 flock of 104 ewes was treated. It was not possible to treat all of 

 them in 1 day but the work was done on separate days whenever 

 the time could be spared. Two men were required for the opera- 

 tion, one to hold the animal and spread open the wool, the other to 

 operate the powder gun. 



Ewe infested with Lice 



Two types of hand powder guns were used in the test. One 

 was of the ordinary barrel and plunger type ; the other, the rotating 

 fan type. The latter type makes considerable noise which tends to 

 frighten the animals. The intermittent operation of the rotary 

 fan generally necessary in dusting a sheep was not conducive to a 

 uniform dust spray when this type of gun was used. The ordinary 

 barrel and plunger gun gave the most efficient service. 



The time factor is an important point in the treatment for ex- 

 ternal parasites. When everything is in readiness the treatment 

 of sheep parasites by dipping requires only about 2 minutes per 



