The Dickinson press., 1904-01-16
SCab in Cattle.

aran, will interest our readers at this
time:
Scab is an infectious skin disease
caused by parasitic mite. 1t has been
we'll known for centuries, all the old
authors referring to it under various
titles. The prevailing opinion concern
ing this disease prior to the last decade
was that in cattle it was due to the con-
d!tion of the blood which lead to skin
eruptions. Why this opinion should
have stood so long is rather astonishing
when it is considered the scab mite Of
sheep has been known for ages and the
S, alb or mango OF sheep was known to
be caused by mite.
AS result Of research, certain inves-
;igators reached the conclusion that the
disease was due directly to mites that
were found inhabiting the diseased parts
OF the skin. This opinion was not at
once adopted, but on the contrary met
with strong opposition from those who
held that scab was due to ii diseased
condition of the blood and IRON others
VINO held the modified view-"that the
mites carried poisonous matter from one
animal to another and in this manner
caused the disease. The errors and
uncertainties which came down to us
though centuries of controversy were
finally and for all time dispelled by
conclusive experiments upon animals
made during the first half of this cen.
tnry. 1t was shown that scab does not
develop and cannot be produced without
the parasites. The complete life cycle
of mites was studied and demonstrated
from eggs to the adult parasite. 1t was
shown that the mites are always the
offspring of ancestors, the same as are
larger animals.
1t was shown that the mites caused
scah; and that diseases Of the skin re-
sembling scab where the mite was not
present were not SO infectious and disease
could not be reproduced.
Scab, or Texas Itch, as it is known in
the west is caused by mite known as
"Psoroptes Communis Bowls; mite
that while it resembles in appearance,
lille history, size and habits the same
mite in sheep, will not produce scab in
sheep; and the scab mite in sheep will
not cause scab in cattle. All animals
subject to scab appear to have an indi-
vdual mite.
The mite of the OK is visible to the eye
under favorable conditions. If the mite
is isolated on a dark background. as on
black paper. they can be seen plainly as
they move about. Sunshine or mild
heat will Cause the mite to move. They
will be found in the crusts and on the
hair. They infect the back, shoulders,
rump and in very bad cases are found
we'll down on the legs.
The female mite, which is the largest
CT .iuc tn N
skin, six legged larva is hatched, this
they pair and the females lay their eggs
and die. Gerlach estimated that it took
about fourteen or fifteen days for the
generation of mites from the time Ct
pairing to maturity of the next genera
ton Dividing the time as follows,
eggs hatch in 3 ora days, 3or days
after birth the larva moult and the fourth
pair of legs appear; when 7 to 8 days old
the mites are ready to pair: allowing
several days for pairing. another genera
ton of eggs may be laid ii orr days
after the first generation. Accepting
this estimate, the one generally conced-
ed to be correct, as an average, each
generation of 10 females and males in
three months time would reach the
sixth generation and the entire family
would number about 100000 females
and 100000 males. This will give an
idea of the rapidity OF the spread of
scab.
The symptoms OF scab are as follows:
Itching, irritation" formation OF papu-
:. ndamatior, exudation of serum a id
t,c formation of crusts, or scabs, uuder
and near the edge of which will be found
the mites. AS the parasites multiply
they seek more healthy parts, spreading
out and taking in more territory and ex-
tending the disease. The animals scratch
md dig, will spend great deal Of time
licking themselves, will rub on posts
hard enough to often break the posts off,
and will scratch on wire until the skin is
bloody. The scab gets thicker and
harder AS the disease progresses, until
in the later stages the back, sides,
rumps and shoulders are all one scab.
1t feels stiff and boardy, the hair stands
straight and is rubbed off and the skin
raw in spots. The skin under the scab
is dry and hard. cracks and fssures ap-
pear and the skin resembles skin of an
elephant or large boar. The hair pulls
out in fakes raising the scab with it.
vanced, it will stand and refuse to move.
The appetite is good, but no amount
OF food will strengthen until the mites
are killed.
The only cure is to dip or 10 days
apart, and the most desirable dip is the
old fashioned lime and sulphur dip
bout I6 pounds of unslacked lime and
"a pounds OF flowers Of sulphur to 100
gallons of water, applied hot. This is a
certain cure it all the necessary pre-
causions are taken. Every animal should
be dipped two minutes in tank deep
enough to cover all over, and repeated
in or 10 days. The first dip kills the
mite, the second kills the larva that are
hatched from the eggs:
This disease exists in Montana, the
northwest territories, and in North Da-
kota as we'll as in some of the southern
states. 1t will spread over an entire
range in one summer and il followed bv
hard winter will cause very heavy
losses. Scab does not show very bad in
the summer months but contrary TO
many reports does not disappear, but
owing to the summer rains and improved
condition OF the animals on grass it can
not make the impression that it does in
the fall and winter months. The rains
wash out the scab and with it great
many of the mites To this fact is due
the improved condition in the early sum-
mer. AS soon as the dry season com
mences scab will again appear and y
the time the cold weather sets in Il e
animal will be covered with mites.
Instructions for making the dip. tank s
and general ,nanapcmcnt of Sc:b IL, any