SHEEP SCAB. 15 



TREATMENT. 



The only rational treatment for common scab consists in using 

 some external application which will kill the parasites. Feeding 

 sulphur and salt and various other preparations to sheep will not 

 destroy the j^arasites and consequently will not effect a cure. Hand 

 dressing, or " spot doctoring " as it is commonl}^ called, consists in 

 soaking the affected parts with a medicated solution of strength 

 sufficient to kill the mites. This acts as a palliative and tends tem- 

 porarily to check the disease, but will not effect a cure. The only 

 conditions under which hand dressing can be advised are (1) when 

 the disease develops in a few sheep of tlie flock during severe winter 

 Aveather or just prior to lambing, in which event the infected sheep 

 should be isolated from the flock and may be given a hand dressing 

 to keep the disease in check until arrangements can be made for 

 dipping the entire flock; (2) all sheep affected with hard scab should 

 be separated from the flock just prior to dipping and the crusts or 

 scabs broken up with a cob or stick and the spots soaked well with 

 dip a little stronger than is used in the bath. It can not be too 

 strongly emphasized that hand dressing, or spot doctoring, will not 

 cure scab; in fact, in mam^ cases it is responsible for spreading the 

 disease, for the reason that the sheepman too often depends on this 

 method to effect a cure. Meantime the disease is spreading through- 

 out his flocks and the premises occupied are becoming infectious. 

 Temporizing methods in dealing with sheep scab are exjiensive in the 

 long run and should never be used or depended upon. 



DIPPING SHEEP. 



Dipping consists in immersing the sheep in a medicated solution 

 that will kill the parasites, and is the only practical method known 

 for eradicating the disease from the flock. The usual method is for 

 the sheep to enter one end of a vat filled with dip, through which they 

 swim, and leave the vat at the opposite end. The dip or solution 

 should be used warm in order that it may penetrate the fleece and the 

 hard scabs or crusts. Two dippings 10 to 14 days apart are neces- 

 sary to effect a cure. The first dipping kills the live mites but does not 

 destroy the eggs. Within 10 days after the first dipping the eggs 

 on the skin at that time will have hatched out, but the new mites 

 will not have reached maturity or laid eggs. The second dipping 

 kills the new mites hatched subsequently to the first dipping. 



As a basis of practice it may be stated that one dipping will not 

 cure scab. Sheep in full fleece will retain more of the dip in the 

 wool than freshly shorn sheep or lambs with short wool. If the 

 active principle of the dip used is only slightly volatile and the 



