90 DISEASES OF SHEEP. 



THE FLUKE. 



The fluke is a disease of long duration, closely related to 

 the rot, and not less destructive. At first it shows no strik- 

 ing symptoms, and can be easily recognized only in its more 

 advanced stages. The eye of the patient is pale and 

 covered with a tough mucus. The animal becomes weaker 

 and weaker, loses flesh and its belly swells up. Pressure 

 in the region of the liver causes pain. The appetite dim- 

 inishes while the thirst increases, and the animal frequently 

 licks woodwork, whitewashed walls, the ground, etc. 



The excrement is discharged in large lumps or balls, and 

 is sometimes pasty and thin. The progress of the disease 

 is almost identical with that of the rot, and the same is 

 true of the dead bodies. Water is efiused under the skin in 

 the different cavities of the body, the fat has disappeared 

 entirely, and all parts are pale and flaccid. The most 

 important difference between the fluke and the rot is the 

 condition of the liver, which in fluke is very friable, bloated 

 and twice as heavy as in the healthy state. On the surface it 

 is of a pale bluish or lead color and covered with knots or 

 water-blisters. The gall-bladder mostly contains an exces- 

 sively large quantity of bile. In the gall-bladder and the 

 biliary ducts are found large numbers of flat, oval worms, 

 which are generally four or five lines broad and an inch 

 long. 



Fluke is generally even slower than rot, and the life of 

 the patients may be prolonged for several years if the treat- 

 ment be good. Nothing certain is yet known concerning 

 the cause of fluke. It appears most frequently, like rot, 

 in wet years, after poor food, etc. The worms are formed 

 spontaneously, like all other worms of the viscera ; and the 

 opinion that they are introduced into the body with the 

 food, drink, etc., must be considered as erroileous. 



