Parasites and Parasitic Diseases of Sheep. 835 
The softening of the liver is what gives the name of “ liver rot ” to 
the disease. The biliary canals and gall ducts are much thickened 
and enlarged and often are marked by ridges on the surface of the 
liver. 
Treatment.—The two remedies which have been found satisfactory 
are male fern and kamala. According to some writers, however, 
kamala is much less efficacious than male fern. 
Oleoresin of male fern is administered as follows: Give by mouth 
3 to 5 grams of the male fern (from ? of a teaspoonful to 14 tea- 
spoonfuls), according to the size of the sheep, in 10 mils (24 tea- 
spoonfuls) of a nonpurgative oil, in the morning, two hours before 
feeding. Administer the treatment on five consecutive mornings. 
The male fern should contain 24 to 25 per cent of filicine and 3.5 
per cent of filicie acid. 
Powdered kamala is administered as follows: To yearlings and 
older sheep give 15 grams divided into two doses of 7.5 grams (2 
drams) each, and give at 12 to 24 hour intervals. The entire 15 
grams may be given in one dose to a strong animal or -divided into 
five doses for weak ones. After treatment sheep are dull for 3 to 
5 days, they lie down a great deal, eat little or may stop eating for a 
day or two, and have a diarrhea. The flukes are said to die in 3 
to 8 days. 
It is advisable to have these drugs administered by a competent 
veterinarian. 
Prevention—The manure from infected sheep should not be put 
on pasture, especially on wet ground. Sheep should be kept off wet 
pasture in places where fluke is prevalent and swampy areas should 
be drained, filled, or fenced off. Dressings of lime and salt on pas- 
tures in June, July, and August have been recommended for killing 
the embryos and larve of the fluke and for killing and repelling 
snails. It is said that sheep never become infected with flukes on 
salt marshes. Infected sheep should be isolated and either treated 
for fluke or butchered before they have lost condition and become 
unfit for food. Where fluke is present in a flock, it is advisable to 
treat the flock at the beginning of winter after the danger of fresh 
infestation is past. Frogs, toads, and carp are useful in the control 
of snails. Safe drinking supplies must be provided for sheep as 
the infection may be water-borne. 
The Oregon agricultural experiment station has recently recom- 
mended the addition of copper sulphate (bluestone) to standing water 
or streams in pastures to destroy the snails which are the necessary 
intermediate hosts of liver flukes. After ascertaining the volume of 
standing or running water to be treated, add one ounce of copper sul- 
phate to 7,800 gallons of water or about one part of copper sulphate 
to one million parts of water. This will kill snails in 48 hours, but 
