PARASITES AND PARASITIC DISEASES OF HORSES i. 
Areca nut may be of value for the removal of tapeworms from 
the horse. Areca nut, freshly ground, may be given to adult horses 
in doses of from 1 to 1.5 ounces (30 to 45 grams) in capsules after 
fasting the animals for 24 to 36 hours. The drug has a purgative 
action, but if the bowels do not move within four or five hours, it is 
advisable to administer 1 to 2 pints of raw linseed oil. Areca nut 
should not be given to very old or very young animals or to those in 
a weakened condition. 
Kamala may be found to be of value for the removal of horse 
tapeworms. Kamala may be given to adult horses in doses of 1 
ounce (30 grams) in capsule, after they are fasted from 24 to 36 
hours. The drug itself has a purgative action and seldom needs to 
be followed by a purgative. Kamala should not be given to very 
young or very old animals, to those in a weakened condition, or to 
those suffering from febrile diseases, such as influenza, distemper’ 
(strangles), and infectious anemia (Swamp fever). 
Oleoresin of male fern is another drug which may be of value 
for the expulsion of tapeworms from the horse. This drug may be 
iven to adult horses in doses of 3 to 6 drams (10 to 20 grams) in 
capsules after fasting the animal for 24 hours. The drug should be 
immediately preceded or followed by 1 quart of raw lnseed oil. 
The foregoing drugs should be used with caution and given only 
to animals in good condition and presumably able to withstand any 
poisonous effects of the drugs. 
Prevention—In the absence of information concerning the life 
histories of horse tapeworms no definite control measures can be 
recommended. It should be remembered in this connection that 
the eggs present in gravid segments which are eliminated with the 
manure are the starting points of new infestations. Any measures 
which are taken with reference to the proper disposal of manure 
will aid in preventing infestation with these parasites, especially if 
the manure is stored and permitted to undergo self sterilization by 
heating, so far as the destruction of parasite eggs and larve is con- 
cerned. ‘This procedure is described later in this circular. 
ROUNDWORMS 
Roundworms or threadworms comprise the vast majority of para- 
sites which infest horses. These worms, which are also known as 
nematodes, are elongated, cylindrical in shape, and usually tapering 
at both ends. Some roundworms are almost white, some are grayish 
white, most of them are yellowish in color, and some are pinkish or 
blood red. Roundworms occurring in the horse have a considerable 
range of size, the large, intestinal roundworm or ascarid being from 
6 inches to over a foot long, while the small stomach worm is only 
about one-fifth of an inch long. Roundworms reproduce by means 
of eggs which are produced by the female worms. The eggs are 
usually eliminated from the horse’s body with the manure. Some 
species of roundworms must be taken up by an intermediate host in 
which they undergo part of their development, while other species 
are transmitted from one animal to another directly by eggs or by 
larvee which have emerged from eggs. Most roundworms which oc- 
cur in the horse are transmitted directly by eggs and larve, with- 
out the use of an intermediate host. 
