124 ANNUAL REPORTS OF DEPARTMENT OF AGRTCULTTJBE. 



applied from an ordinary sprinkling can than ^\^hen used in wallows 

 or on rubbing posts. 



Hog MANGE. — Experiments on the transmission of mange from 

 one hog to another indicate that the disease spreads much more 

 rapidly and certainly to healthy animals when they mingle with 

 infested hogs than by any other method of exposure. The disease 

 spreads rapidly from one animal to another when the hogs are con- 

 fined in close cjuarters. A herd of hogs confined in a pen with an 

 infected pig all contracted the disease within six weeks. 



Closed dirty pens, previously occupied by infected hogs, appear to 

 be dangerous as a source of infection for about two weeks during 

 severe winter weather and for about 30 days during mild weather. 



A herd of hogs with advanced cases of mange was taken from a 

 pen and turned on alfalfa pasture. Within three weeks the lesions 

 were healed and new hair had started to grow over the infected areas. 

 The hogs continued to improve, and at the end of 2 months no symp- 

 toms of scabies were visible. At this stage healthy sucking pigs 

 were turned in with the herd and they aU contracted well-marked 

 cases of scab. 



Different methods of treatment have been tried but the work has 

 not progressed sufficiently to warrant definite conclusions. 



Ear ticks. — A large number of cattle were treated with various 

 preparations for ear ticks, but no better remedy was found than pine 

 tar, 2 parts, and cottonseed oil, 1 part. A Farmers' Bulletin (No. 

 980) on ear ticks was prepared. 



Cattle scab. — Investigations and experiments on cattle scabies 

 were continued, with special attention to sarcoptic mange Results 

 show that sarcoptic scabies of cattle can be eradicated by four dip- 

 .pings in lime-sulphur or nicotin dips. The interval between dip- 

 pings should be 6 to 10 days. A Farmers' Bulletin (No. 1017) on 

 cattle scabies was prepared. 



ANTHELMINTICS AND TREATMENT FOR INTERNAL PARASITES. 



Results of investigations concerning various remedies for internal 

 parasites have been published in the Journal of Agricultural Re- 

 search (vol. 12, No. 7). Investigations on this subject are being 

 continued . 



BLACKHEAD OF TURKEYS 



Experiments in progress indicate that diet may be an important 

 factor in influencing the susceptibility of turkeys to blackhead. 



ZOOLOGICAL INVESTIGATIONS RELATING TO MEAT INSPECTION. 



An extensive series of practical tests of various methods of curing 

 products containing pork, with reference to those kinds prepared 

 customarily to be eaten without cooking, has been finished, and 

 based upon these tests and other investigations carried on in the 

 Zoological Division, the bureau has issued specifications of methods 

 that have been found to be destructive to the vitality of trichinae. 

 In order to safeguard the consumer of pork products customarily 

 eaten without cooking from the danger of contracting trichinosis 

 from such products, all meat-packing establishments under Federal 

 inspection are required to follow these specifications. 



