PARASITES AND PARASITIC DISEASES OF HORSES 7 



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 grains) 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 

 given 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 linseed 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 larvse 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 roundAvorms are almost white, some are grajdsh 

 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 deposited 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 

 larvae which have emerged from eggs. Most roundworms which, oc- 

 cur in the horse are transmitted directly by eggs and larvae, with- 

 out the use of an intermediate host. 



