Wessington Springs herald. (Wessington Springs, Aurora County, Dakota [S.D.]) 1883-1891, 1883-11-30
The Liyer.Flnke Of Sheep.

The Liver. Flnke Of Sheep.
Fortunately, there have been among
the sheep of America few cases of 1uke.
or liver rot, and it is thought probable
that the parasite which has caused the
loss of so many thousands of sheep in
Great Britain within the last few years
will never become widely spread in this
country. The conditions of climate and
soil in what may be regarded az the
great sheep-growing regions of the
United States are not favorable to the
existence and increase of the worm
known as fuke. But, although it is
hoped that American t1ocks will escape
this evil, there is much of interest in the
life history of this parasite which has
cost the English sheep-owner sc dear.
The liver-t1uke is a sucking worm
related to the common leech, and is
from an inch to an inch and a third in
length. These are found in great num-
bers in the livers of sheep and other
animals infested with the Croft" and
produce vast numbers of eggs. Each
of these eggs under favorable conditions
produces an animal (Which is never
like its parent, never does become like
it, and never lives where its parent
lives.n
In the October number Of Populnr
Science is an article in which Byron D.
Halstead, Sc. d., gives in brief form the
substance of what is known of the
habits Of life of the fluke. He saysIi it
may be safely estimated that a single
tluke may produce half a million eggs
in which no further change takes place
while they remain in the sheep. The
eggs are naturally washed by the bile
into the intestines, whence they are
passed and distributed with the drop
pings. Ifthey fall upon wet land further
changes take place during warm wea-
ther, and an embryo is formed. The
body of this embryo is covered with hair
like arms, Or ella, by the motion of
which itswims through the water. If the
swimming embryo meets the snail Linn
mau ~truncGtu1uS it at once bores into
its victim. Here it will, in July weather,
reach its full growth in two weeks.
From this come multitudes of germs
somewhat similar in form to q stad-
pole" These swim about freely for a
short time; after finding suitable rest
they draw their bodies into a small
sphere, and exude a gummy substance
which protects them from injury. These
cysts remain attached to the heritage
and are eaten by the sheep; but if not
picked up by the sheep within o few
weeks the young flukes they contain
will perish.
If only the greatest degree or ordi-
nary increase were reached a single
fluke might give rise to more than a
hundred million descendants in the next
generation of liver-tlukes proper inhab-
iting the sheep. Gases are known
where t1ukes have lived for more than s.
year. One sheep can not contract the
rot directly from another sheep, and
one snail can not take itfrom its neigh
Dor. The sheep drops the eggs, and,
Matching, the embryos find the snails,
which, after nursing the young 11ukes
through three generations, distribute
the tadpole cercari,e who convey the in
lection back to the sheep, and it there
inhabits the liver and causes the disease.
Other animals than sheep are infested
with the parasite, and rabbits and hares
may be the means of spreading the
plague. In England there seems to be
only one snail which is host to the
young tiukes, and this is said not to en-
ist in the United States, though several
other kinds Of snail belonging to the
same large genus are found here. 1t is
probable that in this country some other
species than that named above serves
as the breeding-place of the intermedi,
ate forms OF Il liver-tlukes.
1t is fortunate that, now that the ma
ture and habits of the tluke are known.
means for preventing it's spread are
found to be at the command of almost
every farmer. Draining wet land will
reduce the number of snails. as it may
also reduce the number of germs OF
other diseases than fiuke, and dressings
of salt and lime destroy them. Where
sheep are suspected of containing fuke
they should be literally fed with salt,
it indeed they should not be at once
killed. BY keeping sheep off low lands
at all times when there is much moisture,
much may be done TO protect them from
the disease. Chicago Tribune.