242 
Liver Rot of Sheep 
purchase of an infected ram, and it is possible that this animal 
introduced the disease upon the farm. Another farmer makes 
a practice of grazing colts with sheep in a wet field, known to 
cause trouble; the colts are believed to eat the dangerous herbage 
without being affected thereby. 
In Montgomeryshire “Blue grass” (Luzula sp.) is blamed as a 
cause of rot, while in Radnor worm casts, locally called “worm 
spews” are regarded as the origin of the disease. 
10. Close grazing is considered by observant farmers and shepherds 
to be one of the factors conducive to attacks of rot, and is of 
course linked with over stocking. Many sheep in competition 
will eat what would otherwise be avoided. Infected snails 
frequently live on mud below thick vegetation, or water contain¬ 
ing cercariae may flow over portions of a field causing a growth 
of rank grasses which only become dangerous to sheep when 
eaten down. 
There is a very general idea throughout the Area that the appli¬ 
cation of lime to grass land is often-followed by an outbreak of rot, 
while one farmer from outside the Area made the same statement 
regarding Basic Slag. Sometimes the statement was merely 
general, but I obtained more or less definite details in seven 
instances. In all cases the ground treated was wet (ill drained) 
grass land with clay (or peat and clay) soil. The explanation 
seems to me to be that the application of lime, etc., to the land 
results in an improvement and “sweetening” of the herbage, 
with a consequent increase in the intensity of grazing by the sheep, 
thus finally reaching the lower grass upon which cercariae have 
become encysted. 
It is evident that condition, as usual, plays its part; on some farms 
and indeed, in some districts, the presence of some flukes may be re¬ 
garded as usual, and those flocks, that have become reduced in condition 
through overstocking, poor pasture, bad weather, exposed situation, 
etc., may suffer as severely from a moderate degree of infection, as a 
strong flock when much more severely parasitised. It is also notable 
that rot and lead poisoning are often to be found at the same time and 
farmers and shepherds state their belief that sheep grazed near lead 
mines are very liable to rot. It is largely I believe a case of reduced 
vitality enabling the flukes present to produce a greater effect. 
The presence of the dropsical swelling or “bag” ( cwd , Welsh) unde 
