24 CIRCULAR 338, IT. S. DEPT. OF AGRICULTURE 



magnesia as a purgative for puppies and young dogs; this may be 

 given immediately following carbon tetrachloride or tetrachlorethylene 

 but an amount sufficient to produce an adequate bowel movement 

 should be administered. Fats, oils, and cream should be excluded 

 from the diet for several days prior to the administration of either 

 carbon tetrachloride or tetrachlorethylene. This applies also in the 

 case of cats. 



Tetrachlorethylene is the drug of choice for the removal of hook- 

 worms from cats, being much safer for use in cats than is carbon 

 tetrachloride. The dose rate and the manner of administration are 

 the same as for dogs. In cases of concomitant ascarid infestations in 

 cats, a purgative should be given as outlined above. 



Ordinarily treatments for worms should not be given to pups until 

 they are weaned, but usually pups 2 weeks old or older may be given 

 tetrachlorethylene with safety. Animals with severe inflammation 

 of the digestive tract appear to be bad risks for this treatment as for 

 most anthelmintic treatments. In connection with the treatment, 

 the same preventive measures given for ascarids should be employed. 



WHIPWORM INFESTATION 



Cause. — The whipworm, Trichuris vulpis (synonym, T. depress- 

 iuscula),is so named because of its resemblance to a tiny whip (fig. 21 ), 

 the short, thick posterior portion of the body forming the handle and 

 the slender, anterior portion, which is about three times as long, form- 

 ing the lash. It is from 1.8 to 3 inches (4.5 to 7.4 centimeters) 

 long. The eggs (fig. 22) produced by the female worms are lemon- 

 shaped, with a knob at each pole. These worms are very common 

 in dogs in the United States but are not known to occur in cats. 



The worm eggs pass in the feces and an embryo develops in each 

 egg. As a rule this development is slow, usually requiring several 



Figure 21.— The dog whipworm, Trichuris vulpis. Male. Enlarged. From Fiebiger, 1912. 



months. When eggs containing these infective embryo worms are 

 swallowed by a suitable host the eggs^ hatch and the young worms 

 develop for a short time in the small intestine and subsequently in 

 the cecum (the blind gut at the union of the small and large intes- 

 tines). Here they apparently enter the mucosa by means of a 

 piercing lancet in the mouth of the young worm. As the worm 

 develops, the anterior portion of the body remains sewed into the 

 mucosa, while the posterior portion hangs free in the lumen of the 

 cecum. The worms apparently become mature in about 3 months. 

 Jn heavy infestations these worms may occur in the colon and rectum 

 as well as in the cecum. 



Symptoms. — These worms not infrequently give rise to a low- 

 grade inflammation at the point where they attach, and as they are 



