150 ANNUAL. REPORTS OF DEPARTMENT OF AGRICULTURE. 



f oiincl ill the lungs of one killed 8 clays after feeding ; the other two 

 are being held for further observations. 



Deparlinont Bulletin 817 and some minor publications on AscaHs 

 Avere issued during the year. 



Several experiments have been carried out relative to the mode of 

 infection of pigs with lungworms {Mcfastro7i(/t/hi.s <iprl and ^1/. hre- 

 rlvaf/inatiis). Pigs ranging in age from 4 days to about a month old 

 were fed larvpe of lungworms from cultures ranging from IT to 35 

 days old. In all cases the results Avere negative. 



TREATMENT AND CONTROL OF EXTERNAL PARASITES. 



Iloo LICE AND HOG MANGE. — From experimental work and trials 

 under actual field conditions, crude petroleum has been found to be 

 the most efficacious remedy for lice and other external parasites of 

 hogs, one dipping being sufficient to eradicate lice and sarcoptic 

 mange. Follicular mange is benefited by repeated dippings in crude 

 petroleum, but is not always eradicated in advanced cases. Crude 

 petroleum may not only be used in dipping vats but also may be 

 economically and effectively applied during warm weather by means 

 of wallow^s. It was the only remedy among a large number tested 

 that was found fully satisfactory for use in hog wallows. In the 

 treatment of sarcoptic mange, lime-sulphur and arsenical dips have 

 been found to be efficacious if four dippings are given at intervals of 

 6 or 7 days. Directions for the control and eradication of hog lice 

 and hos: manere are given in Farmers' Bulletin 1085, which is based 

 upon the results of the investigations mentioned above. 



Sarcoptic mange or horses. — Investigations thus far carried out 

 indicate that repeated applications of lime-sulphur dip or crude 

 petroleum are effective in eradicating sarcoptic mange of horses in 

 ordinary light cases, but that in advanced cases successful results 

 are difficult to obtain. 



Ox warbles. — Experimental work on the difficult problem of con- 

 trolling ox warbles has been continued with reference both to range 

 cattle and cattle confined in smaJl inclosures. In the case of the 

 latter various remedies are being applied to the animals by spray- 

 ing, and in the case of the former by means of wading tanks, through 

 which the cattle have to pass in order to reach their watering places. 

 The results can not be determined until later. 



Screw worms. — Among inexpensive remedies tried in the treat- 

 ment of wounds infested with screw worms, gasoline has been found 

 to be the best, although not entirely satisfactory. 



TRICHINOSIS. 



In order to facilitate the supervision of the various kinds of pork 

 products prepared customarily to be eaten without cooking and those 

 that are cooked in meat-packing establishments under Federal in- 

 spection, the following classification of sausages of kinds prepared 

 customarily to be eaten without cooking has been tested at the Chi- 

 cago station and found to be satisfactory. 



Class A. — Sausages or chopped meats that contain no pork except 

 pork fat or frozen trimmings (that is, trimmings that have been 



