164 PARASITOLOGY. 
normal with a few dark flocculi. As many as a 
hundred flukes have been taken from the ducts of a 
single liver. The liver is unfit for food. 
Symptoms.— Distomiasis or liver rot appears 
mostly among cattle in the United States on account 
of the fact that cattle are grazed on the low lying in- 
fested lands; while the sheep come mostly from the 
high table lands where conditions are not favorable 
for their development into the larval stage. In Eng- 
land the sheep are most often affected on account of 
the reversed conditions to what they are in the 
United States. The symptoms given us by observers 
in that country are as follows: The malady is di- 
vided into four stage$ or periods. 
First period is that of immigration; the flukes 
are small and do not’cause excessive disturbance. 
This period lasts from four to thirteen weeks. 
Second period is that of anemia after the thir- 
teenth week from infestation; the sheep are less 
lively, the mucous membrane is pale, the appetite 
good and the sheep show a tendency to fatten (asa 
result of the stimulus to the liver which causes an 
increased flow of bile). In the latter part of this 
period the appetite diminishes, thirst increases; 
rumination irregular; mucous membrane yellowish; 
may show edema; wool is dry and brittle, and the 
sheep show great weakness. The feces contain the 
ova of the fluke. 
Third Period.—This is a period of loss of flesh; 
the sheep becomes gradually weaker and emaciated ; 
the temperature is irregular, the respiration feeble 
and frequent; pregnant ewes abort; the milk of 
nursing ewes is poor in quality. Oedema is noted 
