530 DISEASES OF CATTLE. 



Treatment. — Medicinal treatment for tapeworms in cattle is usually 

 unsatisfactory, but the bluestone treatment used for stomach worms 

 and mentioned above (p. 528) may be tried. Arsenic in doses of I4 to 

 3 grains has been claimed to give good results in the treatment of 

 calves for tapeworms. 



ROUNDWORMS. 



A large roundworm (Ascans vitularum) measuring 6 to 12 inches 

 in length, sometimes found in the intestines of cattle, especially 

 calves, may cause inflammation and occasionally rupture of the 

 intestine. Infection occurs through the swallowing of the eggs of the 

 parasite in feed or water which has been contaminated with the feces 

 of infested cattle. 



A number of species of small roundworms, varying in size from an 

 eighth of an inch to an inch or more in length, occur in the intestines. 

 Of these may be mentioned the hookworm {Bunostomum pMeboto- 

 mum) and the nodular worm {QiJsophagostomMm, rad'oatum) . The 

 former is about an inch long and is found in the small intestine. The 

 latter are somewhat smaller and are found in the cecum and large 

 intestine. Hookworms, when numerous, may cause anemia and 

 other symptoms similar to those caused by stomach worms (see p. 

 525) . The injuiy to the mucous lining of the intestine from the bites 

 of hookworms may cause severe inflammation, and affords an avenue 

 of infection with the germs of various diseases. The adult nodular 

 worms apparently do not attack the wall of the intestine, but derive 

 their nourishment from the intestinal contents. Several species of 

 small, very slender roundworms (Tnchostrongylus) , less than a 

 quarter of an inch in length, sometimes occur in the small intestine 

 and fourth stomach, and a severe gastroenteritis, or inflammation of 

 the stomach and intestines, has been attributed to them. 



Nodular disease of the intestine, due to young nodular worms 

 which burrow in the intestinal wall during a certain stage in their 

 life history, sometimes apparently produces serious effects, particu- 

 larly in young cattle, but commonly has little or no perceptible influ- 

 ence on the general health. It, however, often renders the intestine 

 unfit for use as sausage casings, and as it is widely prevalent among 

 cattle the loss from this source is considerable. The greenish or 

 yellowish nodules with cheesy contents are frequently mistaken by 

 the inexperienced for lesions of tuberculosis. 



The life histories of the various small roundworms occurring in 

 the intestines of cattle, so far as they ha^-e been worked out, are 

 very similar to that of the twisted stomach worm as described on 

 page 525. 



