STOMACH WORMS (SHEEP) 151 



from a diseased flock. The rational hope lies in reduction and 

 gradual eradication. 



Low, wet pastures are to be avoided. Hillside pastures are 

 much safer so far as internal parasites are concerned; and if 

 possible permanent pastures for sheep should not be used on 

 account of danger from many kinds of internal parasites. Fre- 

 quent changes of grazing ground are desirable for any flock, and 

 especially one infested with internal parasites. In case of 

 stomach worms, the flock should move every two or three weeks 

 on pastures, meadows, fields, sowed crops, etc. 



Medical treatment. — Sheep intended for medical treatment 

 should have no feed during 12 to 24 hours before the medicine 

 is given. No matter which treatment is to be given, it should 

 be tried on a few sheep before treating a very large number. 



The Bureau of Animal Industry has done some careful ex- 

 perimenting in this line, and recommends coal-tar creosote as a 

 satisfactory treatment. This medicine is not expensive and is 

 very easily obtained and prepared but variable in quality. It 

 is important to insist upon getting coal-tar creosote. 



If reliable coal tar creosote can be secured give as a 1 per 

 cent solution; that is, 1 ounce of the creosote to 99 ounces of 

 water in doses proportioned to the age and size of the sheep. 

 Lambs 4 months old take 2 to 4 ounces; older sheep take 3 to 

 5 ounces. If there is any reason to suspect the presence of 

 worms in the intestines, then thymol should be added to the 

 creosote treatment. The dose of thymol is from 30 to 100 

 grains. Each dose of thymol is to be added to the dose of creo- 

 sote after the latter has been mixed and measured, and should 

 then be given immediately. Only fresh crystallized thymol 

 should be accepted, 



Bluestone (copper sulphate) has been accepted as one of the 

 most satisfactory treatments for tliis trouble, but it needs to be 

 given in carefully regulated doses. Best results are secured 

 from repeated doses every 4 to 6 weeks, from spring till frost. 

 This medicine may be made up as follows: Dissolve 1 pound 

 (avoirdupois) of fresh powdered bluestone in 12 gallons of 

 water. For this treatment the animal must be kept off feed 

 from 20 to 24 hours. The dose for a lamb 6 months old is 40 

 CO.; sheep 12 months old, 60 c.c. (about 2 ounces) ; 18 months, 

 80 c.c.; 2 years 90 to 100 c.c. ; calves 2 to 3 months old take 

 about 100 c.c. When the bluestone treatment is used, sheep 



