176 REPORT OF THE BUREAU OF ANIMAL INDUSTRY. 



can not be entirely successful in treatment of sheep with T. fim- 

 briata. Any medicine which would affect the taeniee in these ducts 

 would also affect the sheep seriously. It is doubtful whether they 

 can be killed or driven from the ducts. The continued or repeated 

 administration of remedies that are necessary for expelling these 

 tsenise is also an objection to their use. The parasites are continu- 

 ally appearing throughout the year, and even if those already de- 

 veloped could be driven off, the constant re-infection would neces- 

 sitate other operations for their removal. The cost of the necessary 

 medical treatment seemed to me to more than exceed the good results 

 that possibly might be realized. Further experiments were there- 

 fore delayed until the complete life history of the parasite should 

 be determined. In this history we may hope to find some stage at 

 which we may more profitably administer remedies. I have seen 

 many prescriptions for tape-worms in ruminants in various journals 

 and agricultural papers. Some of them when tried may have proved 

 very efficacious. Unfortunately I have been unable to find further 

 reports concerning the effects or their administration. My own ex- 

 perience leads me to have little faith in them. There is a feature 

 about them which, I have no doubt, has been recognized by the ranch- 

 man who has undertaken to carry them out to the letter, viz : It is 

 the entire inadequacy of the receipt, in prescribing methods of ad- 

 ministration, and medicines of reasonable price as well as of certain 

 efficiency, which shall meet the ranchman's wants. This oversight is 

 of such importance that otherwise good receipts have to be aban- 

 doned. The western methods of treating sheep medicinally must 

 differ from the eastern methods, as the methods of sheep-dipping, 

 sheep-shearing or sheep-husbandry in these sections differ; otherwise 

 the expense of treatment will be so considerable that in view of any 

 uncertainty of cure few ranchmen will undertake it. 



PREVENTIVE TREATMENT. 



The most effective service rendered to man and beast by the phy- 

 sician has been through the prevention of diseases and the preserva- 

 tion of health by hygienic measures. Appreciating this, and real- 

 izing that effective prophylactic treatment of the sheep against in- 

 fection by Tczniafimbriata could not be realized except by the most 

 thorough knowledge of the complete life history of the parasite, I 

 turned my attention to the investigation of its younger stages, and 

 those of other unarmed taenise which were available. Such are the 

 difficulties of this investigation that I have not yet completed the 

 gap in the life history which may exist between the time when the 

 embryo passes from the sheep until it is found, less than a quarter 

 of an inch long, in another sheep. 



From the present knowledge of the development and life of this 

 parasite there have arisen more difficulties in forming rules of pre- 

 vention than I at first supposed would be the case. The presence of 

 the adult and young parasites throughout the year, and the methods 

 of Western sheep ranching are factors which are all-powerful in 

 keeping up the tape-worm disease. The case is not a hopeless one, 

 however, for there are certain phases of feeding and watering the 

 sheep which I think can be advantageously changed, both for the 

 prevention of this and other diseases. 



The feeding occurs on the prairie and in the corral. I would rec- 

 ommend that the ewes with their lambs should be pastured on a 



