Parasites and Parasitic Diseases of Sheep. 23 
of the segments has a fringe on its posterior border. , This fringe may 
be most easily seen when the segment is put in water, where the fringes 
éan float out from the segment. Tapeworms found in the liver or 
pancreas will be this worm and not the Moniezias already described. 
Life history.—As in the case of the Moniezias 
(and this is true of all the adult tapeworms of 
cattle, sheep, and horses), the life history is un- 
known. Presumably it has an intermediate stage, 
probably in an insect or other small animal. 
Distribution.—The fringed tapeworm is a para- 
site of western sheep and is found in the East 
probably only when the sheep have been shipped 
from the West. The infected range is probably 
confined to North Dakota, South Dakota, Ne- 
braska, Kansas, Oklahoma, and Texas, and the 
States west of these. The parasite apparently has 
found conditions most favorable among range 
sheep, and it seems to be losing ground with the 
breaking up of the big western sheep ranges and 
the substitution of small holdings of sheep. 
Symptoms and lesions.—The obstruction of the 
bile ducts and pancreatic ducts causes inflamma- 
tion of these ducts and derangement of the liver. 
As a result there is an alteration in the secretions 
as regards amount and character, which impairs 
digestion and causes a lack of thriftiness. This 
shows in lost flesh and poor quality of flesh and 
wool. Sheep weakened by fringed tapeworms 
may die from the parasitic infestation or from 
inability to withstand. other adverse conditions. 
Infested sheep are commonly hidebound and 
suffer from diarrhea. 
On post-mortem examination the tapeworms 
may be found in the intestine and in the liver 
and pancreas, and the ducts of these glands are 
usually found thickened when infested. In the 
spring of the year fringed tapeworms seem more 
likely to be found in the small intestine than at 
other seasons. 
Treatment.—No successful treatment is known 
for this parasite. Such treatments as have been 
attempted have failed, and all that can be recom- 
mended at this time is careful nursing and good 
feeding. 
Fic. 14.—F ringed tape- 
worm (Thysanosoma 
actinioides. ) About 
natural size. {From 
Stiles, 1898.) 
Prevention.—As in the case of the Moniezias, the fact that we do 
not know the life history of this worm makes it impossible to give 
specific directions for preventing infestation. 
