The Houston daily post. [volume] (Houston, Tex.) 1886-1903, 1897-10-06
rHE SCREW WORM.

NJ; Francis, ID. V. NJ. Texas Agricultural
Experiment Station.
In the first annual report Of this station
/ published some notes on the screw
worm. giving only such facts as i had
witnessed and remedies that / had en-
ployed. After two years of study and OBJ
servaton. during the summer months of
which l have seen cases of the parasite
almost daily, 1t is thought advisable to
give a more exhaustive report of the life
history 20 he insect. together with illus
trauons (see not ID and description (see
note q for Identification
Inc screw worm lis the larva or maggot
OF dipterous insect Q.uclia macellara)
tnat is very common in this portion OF the
country Daring the summer, and Is para
site on man and animals.
The mature insect C'Imago'O Is a fly. q
tr.fie larger than our ordinary house fly.
with yellow head and three dark longi-
Is yellowish green. The Hv lays its eggs
In wound sores. and even in the natural
openings OF man and animals.
In Animal Parasites and Messmates,
by Van Benenden, page li9, there appears
the following: There is another fly IN
steNNo Wn IN is dangerous to man: II Is
or, more correctly. Lucilia hominivora.
Vercammer, a military surgeon of the Bel
gan army, relates that soldier in Mex
leo had his CLOTHS destroyed and the
sides of the roof OF his mouth rendered
ragged and torn, as II cutting punch
had been driven into those organs lis
solder ss,a poo threw up with his spittle more
Professor James Law OF Cornell univer-
stty, In letter to the writer, said: I'm
der the name OF Lucilia hominivora 1t is
SAID to be very destructive to the French
| convicts at Cayenne, the fly depositing ITS
egg. in the mouth and nostrils during
sleep"
No cases In man have fallen under the
| personal observation of the writer.
The fly seems to be well distributed over
| the American continent for DR., .Williston
| of Yale college writes that at occurs
everywhere from Canada to Patagonia"
| Although so generally distributed, only in
| tance In the United States. or all our do
INVESTIGATED anima-e cattle suffer the most
| from IT'S ravnges. They occur In wounds
from horns castrating, spayng,, brand,
| often where ticks have burst on the brts.
| ket flank, or just behind the udder of
| cows. They often occnr in the vulvae of
| fresh COWS, especially If there has been
| & retention of the pacenta or afterblrth.
| Young calves are almost invariably at
fected in the navel and often in the
| mouth causing The teeth to fail out. One
case occurred in the first stomach pauiIch
| or runen) that is worthy of mention.
Last September the writer had occasion
| to kill a Jersey bull calf. probably 2
months old that had screw worms in
| both hind legs just above the hook joint.
| On opening the abdomen | found hair
| balls In the stomach Tumen) and, to my
| surprise. about twenty-five fully matured
| screw worms almost buried in the wall
of that organ ] placed some OF the
woi ms in moist earth, and in ten 10 twelve
| days they Matched out genuine screw
| worm files. How did they come there?
| My opinion is that the calf licked the
sores On his legs, and In doing took in
| some eggs that Matched and developed in
| the stomach.
Horses and mules are not SO often at
| tackled. In them they are usually found
! in barbed wire injuries, and occasionally
| in the sheaths of horses, the vag!nac OF
! mares and the na,velss of colts.
| Hogs are more liable to become affected
| than horses. They are frequently wound
ed by dogs and by fighting, or there may
| be barbed wire injuries, wounds from cas-
| Sheep are comparatively free from at
| lacks unless injured by dogs.
In all animals alike, the eggs, after be-
pE no BY hs ny n Ths aa s enss Of
| time this requires seems to vary with cir
cumstances. My present opinion. is that,
| II the eggs are laid in a moist place and
| on a warm day, 1t requires less than one
hour whereas, II laid in dry place they
| seem to dry UP and lose their vitality.
| small and easily overlooked. IL they are
| hatched on the surface in drop OF blood
| from a ruptured tick. for instance. they
| attempt to perforate the skin. and II
| Matched in wounds they at once become
| buried out of sight They seem to attach
themselves by their heads, and burrow
| vouring the soft flesh. Occasionally few
| are seen moving from one place. to an
other, but usually they>Temain fixed at
one point. The worms grow steadily In
size. and the hole in the flesh becomes
| larger every day. Sometimes the worms
make. tunnels. but. not to any depth; they
usually stay on the surface. They evil
IDENTIFY produce considerable irritation, for
| the part Is always swollen and constantly
bleeding. This swollen. gaping appearance
of the wounds together with the constant
| discharge of blood, are Characteristic OF
the presence of worms 1t seems TO re-
qpire about a week for the worms 10 be-
about five-eghths 10 six-eighths OF an
| inch long They then leave the sore and
| go into the ground, where they pass their
! nino to twelve DAVIS. or several hundred
hatched out by the writer. the shortes.
! time was nine days and the longest four
! teer days. but in the majority OF cases II
| required from nine to twelve days. While
| the larvae are thus developing the flies
ere constantly laying fresh eggs In the
wounds, so that the young worms take
the places of the matured ones, and thus
! keen IN a constant and progressive loss
OF tissue II the worms are not killed
| they eat constantly deeper, and often kill
| the animal. Sometimes the abdomen Is
| opened and the bowels escape-as is es-
| pecially liable In case Of heifers spayed
| through the abdomen AT other times
| tail u eaten off or extensive caverns are
| made into the muscles.
| The treatment usually employed IN these
| cares consist simply OF killing the larvae
| with Cresylic ointment, cainmei. chloro-
| fern or carbolic acid The selection OF
the most suitable remedy VIII vary some
| what with the location, character and ex-
| tent of the sores In some cases BAN
| dages are useful. In others the sores can
| be filled with oakum and few stitches
4 taken. All treatment should be supple
| mented by daubing the margins OF the
1 wound with pine tar to ward off the ny.
| by keeping cattle free from common cat
tie ticks.
CA9ToREA.