ANIMAL PARASITES OF CATTLE. 525 



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

 of infested cattle. 



A number of species of small roundworms .Ciarying 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 phlehoto- 

 mum) and the nodular worm {(Esopha<jostomum radiatum). The 

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

 latter is somewhat, smaller and is found in the cecum and laro-e 

 intestine. (Hookworms, when numerous, may cause anemia and 

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

 519). The injury 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 (Trichostrongylus) , less than a 

 (piarter 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. /One species 

 of small roundworm {Cooperia punctata) burrows in the wall of the 

 small intestme and causes caseous nodules in the mucous lining. 

 This parasite sometimes occurs in very large numbers in the intes- 

 tines of cattle in certain sections of the country, and apparently does 

 considerable damage. ) 



Nodular disease of the intestine, due to young nodular worms 

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

 life history, sometimes apparently produces serious efl'ects, particu- 

 larly m 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 occurrmo- in 

 the intestines of cattle, so far as they have been worked out, are 

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

 page 519. 



Treatment jor iidestlual roundworms. — The preventive measures 

 are similar to those recommended in the case of the twisted stomach 

 worm (p. 521) . Medical treatment is generally not very satisfactory. 

 According to the Oklahoma Experiment Station, the addition of 1 

 per cent of tobacco to the bluestone solution used in the treatment of 

 stomach worms in sheep i§ effective in the removal of hookworms. 

 The bluestone and tobacco mixture described on page 524 may be of 

 value in the treatment of hookworms in cattle. It is asserted by " 



