LECTURE XXIII. 



EXTERNAL PARASITES. 



Lice (phthiriasis), treatment. — (i) Bathe the affected parts 

 with corrosive subhmate in water 15 grains to the pint; or (2) 

 tobacco water (steep for an hour two ounces of tobacco to each 

 quart of water) ; or (3) for small surfaces, as mane and root 

 of tail, kerosene one part, linseed oil 10 parts; or (4) Prof. 

 Riley's kerosene emulsion made as follows : kerosene 2 gallons ; 

 soft soap 5<2 lb. ; water one gallon. Dissolve the soap in water 

 by boiling and add kerosene slowly while still boiling. Churn 

 ten minutes and dilute by adding 8 times its bulk of water. 

 This is cheap, harmless and satisfactory. 



FIG. 35. SHEEP TICK AND ENLARGED PROBOSCIS. 



Mcluphaijus Linus. Properly a sheep louse. 



Any treatment for lice should be repeated several times at 

 intervals of one week. It is frequently advisable to whitewash 

 stalls and sheds. All harboring litter should be removed and 

 burned. Clipping is a great aid in the treatment of external 

 parasitism. 



It is difficult to treat sheep successfully for either lice or 

 scab without shearing. 



For cattle, horses and young stock, in cold weather dust 



