2 FAEMEES BULLETIN "713. 



While the disease is highly contagious, insidious in its nature, and 

 severe in its effects, it yields readily to proper treatment and is easily 

 «ured. A sheep owner should never allow scab to remain in his flock, 

 as it can be easily eradicated by proper dipping. 



Common scab was formerly the greatest drawback to the sheep 

 industry of the United States, but during the past decade great 

 progress has been made in its eradication. The system of grazing 

 sheep on the open ranges of the western part of the United States 

 was such that the flockmasters had great difficulty in keeping the 

 flocks free from scab. The sheep were very frequently exposed to 

 the disease by infectious ranges and trails. " picking up strays " from 

 infected flocks, and in many other ways. It became desirable for the 

 Department of Agriculture to extend aid to the industry by control- 

 ling the interstate movement of sheep to prevent the carrying of the 

 infection from one State to another. Arrangements for cooperative 

 work with the live-stock sanitary authorities of the various States 

 concerned were made by the Bureau of Animal Industry with the 

 object in view of completeh-^ eradicating the disease. This work has 

 been in progress for about 10 years, and during that time the dis- 

 ease has been redueed to a minimum over the entire area and nearly 

 all the formerly affected States have been released from quarantine. 

 The disease has been so nearly eradicated that at present the economic 

 losses from this cause are practically nil. In vieAv of the highly con- 

 tagious nature of the disease, however, it is very important that the 

 work of eradication be pushed to completion in order to prevent the 

 disease from again becoming prevalent. 



With our present knowledge of and experience in sheep-scab 

 eradication work, it is comparatively easy to reduce the infection to 

 a point where it ceases to cause economic loss, but the complete eradi- 

 cation of the parasite over such vast areas is a problem requiring 

 patience and diligence. Where the eradication work is supervised 

 by a well-organized force of trained field men, the percentage of in- 

 fected flocks can be reduced very rapidly until it reaches a fraction 

 of 1 per cent; but to reduce that fraction to zero requires very care- 

 ful and systematic work, with the full cooperation of the sheep 

 owners. As soon as the disease is reduced to a point where the 

 economic loss is little or nothing, many sheep owners lose sight of 

 the importance of continuing systematic efforts for complete eradica- 

 tion. It is necessary, however, for the protection of the sheep in- 

 dustry that the efforts be continued until the pest is completely 

 eradicated. 



Since the quarantine has been removed and compulsory dipping 

 discontinued the sheep owners in some communities have allowed 

 their dipping vats to go to ruin through lack of use and care. All 



