CHAPTER XX 

 DIPPING SHEEP FOR TICKS AND SCAB 



This chapter discusses the following phases in regard 

 to dipping: (i) The objects sought from dipping; (2) 

 The two classes of sheep dips ; (3) The basic element in 

 sheep dips; (4) The dipping plant ; (5) The reason for 

 dipping; (6) Facts that bear upon the work of dipping; 

 (7) Care of the animals subsequently to dipping; (8) Re- 

 moving parasites by other methods; and (9) How far 

 dipping is a necessity. 



The objects sought from dipping These are three: 

 (i) The removal of external parasites; (2) the improving 

 of the condition of the skin ; and (3) increasing growth in 

 the wool. The first of these objects is the most important 

 by far. 



Prominent among the external parasites which dip- 

 ping aims to remove are sheep ticks and the mites that 

 produce sheep scab. The rate of increase in both is very 

 rapid. Gerlach has estimated that the possible increase 

 of the mites in sheep scab in 90 days is 1,000,000 females 

 and 500,000 males. Other parasites may also be destroyed 

 by dipping, as sheep lice and maggots. 



The dipping of sheep is of comparatively recent 

 origin. The sheep industry in America, for instance, 

 flourished for at least 75 years prior to the introduction 

 of dipping, and in Europe it flourished for centuries before 

 this method of fighting parasites had been discovered. 

 The shepherds of the Old World had fought the battle 

 successfully against parasites in sheep for centuries be- 

 fore the introduction of dipping. They did so through 

 the practices of smearing and pouring. But the efficacy 

 of these practices for the removal of parasites compared 

 with dipping are so far behind the latter as, in a sense, 



