368 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



Nodular disease of the intestine, due to young hook worms, and 

 nodular worms which burrow in the intestinal wall, as a rule seems to 

 have little effect on the health of infested animals, but often renders 

 the intestine unfit for use as sausage casings. As nodular disease 

 is widely prevalent among cattle, the loss from this source is con- 

 siderable. The greenish or yellowish nodules with cheesy contents 

 are frequently mistaken by the inexperienced for lesions of tuber- 

 culosis. 



The life histories of the various small roundworms occurring 

 in the intestines of cattle have not been worked out, but in general 

 they are very likely similar to that of the twisted stomach worm as 

 described above. 



Treatment for Intestinal Roundworms. The preventive meas- 

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

 stomach worm (p. 363). Medicinal treatment is generally not very 

 satisfactory. Powdered thymol, in doses of 200 grains or more, 

 has been recommended, but it often fails to have the desired re- 

 sult. It is claimed by one author that 2 to 3 drams of rectified 

 empyreumatic oil in a mucilaginous emulsion, followed the next 

 morning with a purgative of 1 to 1^ pounds of sulphate of soda, 

 will expel the large roundworms (Ascaris vitulorum). 



PROTOZOA. 



A number of species of protozoa have been reported as para- 

 sites of the intestines of cattle. To one species has been attributed 

 a serious disease of cattle in Switzerland known as red dysentery, 

 but as yet no cases of this disease in American cattle have been re- 

 ported. 



FLUKES IN LIVER AND LUNGS. 



Two species of flukes occurring in the liver and lungs are 

 known to affect cattle of the United States. These parasites are 

 flat leaf-like-worms ; one of them, the common liver fluke (Fasciola 

 hepatica), is less than an inch in length, while the other, the large 

 American fluke (Fasciola magna), is considerably larger when full 

 grown. In their life history these flukes depend on snails as inter- 

 mediate hosts. At a certain stage of development the young flukes 

 leave the snails, become encysted on stalks of grass, and finally may 

 be swallowed by grazing cattle. Stiles states that flukes may produce 

 a serious, often fatal disease, more especially in younger animals. 

 The symptoms are somewhat similar to those produced by worms 

 in the stomach. The first symptoms are generally overlooked, the 

 disease not attracting attention until the appetite is diminished; 

 rumination becomes irregular, the animals become hide-bound, 

 and the coat dull and staring. The staring coat is due to the con- 

 traction of the muscles of the hair follicles. The visible mucous 

 membranes become pale, eyes become dull, there is running at the 

 eyes, and the animal gradually becomes emaciated. As the dis- 

 ease advances the milk supply is lessened, fever appears, there is 

 generally great thirst, but the appetite almost ceases; edematous 

 swellings appear on the belly, breast, etc.; diarrhea at first alter- 

 nates with constipation, but finally becomes continuous. The dis- 



