Parasites and Parasitic Diseases of Dogs 17 



pound of cure. When a pup is infested with worms it is advisable 

 to use medicinal treatment to remove them, and the more serious the 

 infestation the more urgent the need of treatment, but the younger 

 the pup and the more serious the need of treatment the more danger- 

 ous is the treatment. 



In treating dogs for worms, it should be kept in mind that worm 

 remedies (anthelmintics) if potent are also dangerous, and should 

 be prescribed and administered by a competent veterinarian when- 

 ever possible. Among the conditions which make drug administra- 

 tion for worms especially dangerous are extreme youth, age, or 

 weakness of the patient, or the presence of such debilitating diseases 

 as mange or such febrile conditions as distemper. If treatment is 

 imperative under these conditions, diminished doses should be given 

 at two-week intervals, removing part of the worms present each time 

 and thus protecting the patient. Purgation is 

 highly important in connection with anthel- 

 mintics. Adequate doses of a suitable purga- 

 tive should be given, as a rule, with the anthel- 

 mintic, and if evacuation of the bowels does 

 not occur in the course of three or four hours, 

 another dose of purgative should be given. 

 Enemas may also be given if it seems advisable. 



ROUNDWORM INFESTATION 



Cause. — There are two species of roundworms 

 (ascarids) which commonly infest dogs, and 

 both of these occur in the United States. 

 The}'' look very much alike and for practical 

 purposes need not be definitely identified. One 

 of these, Toxascaris limbata^ is a milky white 

 worm (fig. 15) which may attain a thick- 

 ness of about one-twelfth inch (2 millimeters) ; 

 the male is 1.6 to 2.4 inches (5 to 6 centi- ^^^ ^^—^^^ .^^^ 

 meters) long, and the female is 2.4 to 5 inches '^Tscarid'^of ''d^gs, '^tox- 

 (6 to 10 centimeters) or even 5.4 inches (13 ST-' %iV,''-tem^\ 

 centimeters) long. The internal genital tubes, NevefZ-Lemaire 1^12^°' 

 which can be seen through the body wall, do 



not extend in the female into the anterior third of the body. This 

 is the worm most likely to be present in mature dogs. The other 

 ascarid, Belascaris niarginata., is pale butter-yellow in color, of about 

 the same thiclaiess as the preceding, but longer as a rule ; the male is 

 2 to 4 inches (5 to 10 centimeters) long, and the female is 2.4 to 7.2 

 inches (6 to 18 centimeters) or even 8.4 inches (21 centimeters) long. 

 The internal genital tubes extend in the female into the anterior 

 third, and commonly into the anterior ninth, of the body. This is 

 the worm most likely to be present in pups. 



The female worms produce numerous eggs (fig. 16) which pass out 

 in the feces and develop under favorable conditions of warmth and 

 moisture, in the course of two or three daA'S under very favorable 

 conditions, to the stage where each ^g^ contains an infective embryo 

 worm. ^^Hien such eggs are swallowed by dogs in contaminated food 

 or water or in other ways, the eggs hatch and the yoimg worms enter 



Fig. 15. — The small white 



