Skin Diseases. 283 



Sheep suffer mucli in some localities from the larva of 

 the blowfly, laid on any damp or dirty part of the skin, as 

 on the tails and thighs when scouring. In such neighbor- 

 hoods the existence during summer or autumn of a dark 

 wet spot on the skin, of a white tuft of wool, or of wriggHng 

 of the tail will demand ijaamediate attention. 



Treatment. Clip off the wool and filth, pick off all 

 maggots and apply oil of turpentine or of tar 5 oz., 

 camphor 1 dr., asafcetida ^ dr. ; dilute carbolic acid or 

 kerosene may be used in the absence of anything else. 

 To prevent .the attacks use the sheep dip advised for scab, 

 or cut off the dirty wool and apply carbolic acid 1 part, 

 water 50 parts. 



SHEEP-TICK. HIPPOBOSCA (mELOPHAGUS) OVINA. 



This is a dipterous insect degraded by the non-develop- 

 ment of its wings. It is best met by the dips advised for 



Fig. 55. 



Fig. 55 — Sheep-Tick with egg. Magnified. 

 scab. It is especially important to dip lambs, after affected 

 ewes have been shorn, as the insects migrate to the young 

 where they find more wool to shelter them. 



FLEAS. 



These, hke the hippoboseidne, are wingless diptera. We 

 have a variety each for the dog, cat, hen and dove, and in 

 tropical America the puJex penetjmis or Chigoe which 

 burrows under the skin and there lays its eggs to be 

 hatched out in the flesh. Persian Insect powder is one of 



