84. Farmers’ Bulletin 1150. 
walls to the body cavity. Here they wander over the surface 
of the viscera and the walls of the body cavity and as a rule finally 
perforate the capsule of the liver and reach the extremities of the 
biliary canals. <A few go astray and perforate the diaphragm, 
getting to the lungs. In the liver the young flukes grow and make 
their way down the canals, the larger ones being found in the bile 
ducts, and begin again the life cycle with the formation and passage 
of eggs. 
Ditinaseneon his parasite occurs over a large part of the world, 
where low, wet pastures and the presence of suitable snails make it 
possible for it to exist. In the United States it occurs on the At- 
lantic and Pacific coasts in places, and along the Gulf of Mexico. 
In these regions it occurs in wet pastures, especially along rivers 
and tributary streams. The States in which the fluke is most preva- 
lent are Washington, Oregon, California, Texas, Arkansas, Louisi- 
ana, Alabama, and Florida. It is also prevalent in Porto Rico and 
Guam. 
Symptoms and lesions.—Sheep are likely to put on fat and seem- 
ingly improve in condition in the early stages of liver-fluke disease, 
usually in the summer and fall, apparently as a result of a stimula- 
tion of the functions of the liver. Later, however, they lose in con- 
dition. The skin and mucous membranes are paler and the animal is 
less lively. The animal feeds less and ruminates less. Edema ap- 
pears as the composition of the blood is altered, and may be seen as 
swellings along the pendant portions of the body, for example, in 
the region under the jaw. During the winter the sheep becomes 
leaner, breathes rapidly and feebly, and is dejected. A diarrhea is 
usually present at a late stage of the disease. 
Animals may die at any stage of the disease, but if they survive 
the attack the flukes leave the sheep in the spring and a part of the 
damage is repaired. Total recovery is hardly possible, as the liver 
is burdened with scar tissue in the areas where the flukes have been. 
The disease may be diagnosed from its symptoms, if one is familiar 
with it, but a safer diagnosis is based on the finding of the worm 
eggs in the sheep manure. 
For the purposes of the farmer and sheepman the surest diagnosis 
is made by killing a sick sheep and making a careful post-mortem 
examination. If the ducts of the liver are carefully slit and exam- 
ined, the flukes will be found as dark, leaflike objects which, if 
watched a short time, will show movement. The liver may be 
washed in a plentiful supply of clear water as it is cut up, and the 
water examined for the flukes that may wash out. The liver of 
infected sheep is softened and roughened, and may show channels 
under its capsule. In old cases puckered scar areas are present. 
