INTERNAL PARASITES IN WILD ANIMALS. 
By W. REID BLAIR, D.V.S. 
5 fice frequency of the occurrence of parasitic diseases, par- 
ticularly those due to nematode intestinal worms, has led 
me to devote a considerable amount of time to the investigation of 
the worms infesting our various animals. The fact that each para- 
site or group often demands a different management establishes a 
greater call for a thorough study of the subject. In order to deal 
with parasites so as to cut off their sources of survival, and extir- 
pate them from a locality, a fuller knowledge of their life history is 
demanded than for. simple parasiticidal medical treatment. From 
our experience, I am led to believe that parasitic diseases are an 
important factor in the death rate of probably all zoological col- 
lections. This is perfectly natural. In nature a wild animal roams 
over a considerable surface of ground, and the infection it spreads 
is therefore widely scattered; in a zoological garden, this infec- 
tion, with eggs and embryos of parasitic worms passed in its drop- 
pings, is necessarily confined to a small area: hence small ranges, 
corrals, and cages are naturally areas of concentrated infection. 
Therefore, the mortality of animals and birds due to parasitic 
worms, particularly to nematodes not requiring an intermediate 
host, will be a factor with which we shall always have to reckon. 
Considering the great fatality among young canines and felines 
caused by worms, not alone of the greatest importance is the treat- 
ment after their existence is obvious, but treatment for preven- 
tion is demanded with equal urgency. Probably no known dis- 
order to which the Canidz or Felidz are subject is so destructive 
as intestinal worms. It has been estimated by reliable authorities 
that at least three-fourths of the whole canine race is infected 
more or less seriously by them. 
Among the many different species of internal parasites, some 
are found in the liver. The cruel threadworm selects the heart 
of its victim, death resulting suddenly in a convulsion, or it may 
be deferred for a time, during which the animal is racked by 
agonizing pain. In the nasal cavities, the lungs, blood and muscu- 
