16 Farmers’ Bulletin 1150. 
danger from hemorrhage and infection. Every year numerous ani- 
mals die from screw-worm infestation. 
By way of prevention it is essential that carcasses of animals dying 
from any cause should be promptly burned or otherwise disposed of 
so that flies can not breed in them. If they are buried they should 
be buried in quicklime and the entire carcass should be at least two 
feet under ground and the soil tightly packed. Shearing cuts and 
other injuries from accident or operations should be coated with 
pine tar to prevent flyblow. Flytraps are valuable as control 
measures. : ; 
Sheep-wool maggots belonging to a number of species® are some- 
what similar in habits to the screw-worm fly. Related flies have 
become a very serious pest to sheep in Australia. The flies deposit 
their eggs or young in the wool. Infested sheep are sometimes 
treated by clipping the wool about infested parts and applying con- 
centrated dip, 
chloroform, or 
mixtures of tur- 
pentine and tar. 
It isalso advised 
that lambing 
should occur as 
early as possible 
Fic. 10.—Screw-worm maggot, side view. Enlarged. (From and shearing be 
Bishopp, Mitchell, and Parman, 1917.) carried on be- 
fore the warm 
weather sets in, to reduce the chance of infestation. The wool of 
sheep, especially those affected with diarrhea, should be kept trim- 
med about the tail region to prevent flyblow at this place. <A prac- 
tice which has been found of considerable value in Australia consists 
in spraying the tail region of the sheep with 0.2 per cent solution of 
arsenious oxid just before lambing time. This can be done quickly 
and easily, is cheap, and affords considerable protection. The prompt 
destruction of carcasses is as important in the control of these mag- 
gots as it is in the control of the screw worm. 
INTERNAL PARASITES. 
The internal parasites include tapeworms, flukes, roundworms, and 
a few other forms, such as the maggots causing grub in the head, 
the tongue worm, and the one-celled forms, or Protozoa, these last 
being microscopic in size and of comparatively little known im- 
portance in the United States so far as_sheep are concerned. 
The following discussion includes the more important of the nu- 
merous kinds of internal parasites that infest sheep. 
6 Phormia regina, Lucilia sericata, and others. 
