580 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



This method of treatment has been followed not only by us per- 

 sonally, but in answer to inquiries it has been recommended during 

 the past two years. So far as information could be obtained the re- 

 sults have been most successful. Of course no treatment succeeds 

 where an animal is already so badly infested as to show marked 

 weakness and emaciation. We have yet to record fatalities from this 

 method of treatment, although some farmers have used larger doses 

 or made a stronger solution than has been recommended. It can- 

 not, however, be too emphatically stated that he who modifies either 

 the size of the dose or the strength of the solution is taking his own 

 risks and at the expense of the flock. 



The practice of simply treating those animals in the flock that 

 begin to show signs of parasitism is hardly worthy of notice. The 

 entire flock should be treated at the same time, for while other sheep 

 may be able to withstand the presence of the parasites, they serve as 

 a source of infection. While the tapeworms are being voided the 

 flock should be confined to one place, the droppings with the seg- 

 ments of worms collected and destroyed or removed to a place to 

 which the sheep do not have access, to guard against a recurrence of 

 this disease. 



LIVER FLUKE (FASCIOLA HEPATIC A ; LINN). 



The liver fluke is a broad flat worm found in the liver of sheep, 

 goats and cattle. Its life history is one of great interest. The eggs 

 are produced in immense numbers and pass through the gall duct to 

 the intestine and out with the faeces. Those that fall in favorable 

 places as puddles of water escape from the shell. They are very del- 

 icate, covered -with hair to aid in swimming and have a proboscis to 

 puncture the body of a variety of small snails. It is necessary that it 

 should find a snail in a day or two otherwise it will die. If it should 

 find a snail it punctures the body to the respiratory tract, and be- 

 comes encysted. It is here known as the sporocyst and may divide 

 into several bodies, five to eight and these are developed into rediae. 

 The rediaB are about one-twelfth of an inch long. These rediae are 

 liberated from the sac and these in turn develop within themselves 

 from fifteen to twenty bodies known as cercaria? and it is these 

 latter that escape from the snail. The cercariaa after some slight 

 change become encysted on grass or wherever it may happen to be. 

 In this stage it will resist drying, temperature changes, etc., and is 

 the form in which it is swallowed by the sheep. The swallowed cyst 

 has the shell digested by the action of the gastric juice and the young 

 soon finds its way to the liver where it becomes an adult and the 

 process is repeated. By some form of migration the flukes may find 

 their way into lungs. The eggs seem to be passed through a period 

 of a month or more during the summer, the first development of the 

 offspring takes place in the summer and the cyst comes on later in 

 the fall. 



The symptoms of fluke disease are not all recognized by the 

 stockman. There is a period of migration from the intestine to the 

 liver lasting during the summer that is attended by little disturbance. 

 During the late fall and winter the affected sheep show a lack of. 



