526 DISEASES OF CATTLE. 



one author that 2 or 3 drams of rectified empyreumatic oil in a 

 mucilaginous emidsion, followed the next morning with a purgative 

 of 1 to H pounds of sulphate of soda, will expel the large round- 

 worms (Ascaris vitulorum). 



PROTOZOA. 



A number of species of protozoa hare been reported as parasites of 

 the intestines of cattle. To one species has been attributed a serious 

 disease of cattle in Switzerland knoA\-n as red dysentery, but so far 

 comparatively few cases of this disease have been recorded in America. 

 It is probably more common than is generally supposed. Calves 

 particularly seem most likely to be affected. 



FLUKES IN LIVER AND LUNGS. 



Tw^o species of flukes occurring in the liver and lungs are lmo^^^l 

 to affect cattle in the United States. These parasites are flat, leaf- 

 like worms; one of them, the common liver fluke 

 {Fasciola Jiepatica, fig. 19), is less than an mch in 

 length, while the other, the large American fluke 

 Fig. i9.-The common {Fasciola magna, fig. 20) , is considerably larger when 

 uver fluke (Fasciola. f^H growii. In their life history these flukes depend 

 on snails as intermediate hosts. At a certain stage 

 of development the young flukes leave the snails, become encysted 

 on stalks of grass (fig. 21) , or fall into drinking water, and finally may 

 be swallowed by cattle. Stiles writes as follows : 



Flukes may produce a serious, often fatal, disease, more especially iu 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 xintil the 

 appetite is diminished; rumina- 

 tion becomes irregular, the ani- 

 mals become hidebound, and the 

 coat dull and staring. The star- 

 ing coat is due to the contraction 



of the muscles of the hair follicles. -r- on rrv, , . ■ » ^ , -c ■ , 



. . Fig. 20.— The large American fluke {Fasciola ma^na). 



The visilne mucous membranes 



become pale, eyes become dull, there is running at the eyes, and the animal gradually 

 becomes emaciated. As the disease 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. ; diaiThea at first alternates %vith constipation, 

 but finally becomes continous. The disease lasts from two to five months, when 

 the most extreme cases succumb. 



Most of the German cattle are said to be infested with liver flukes, but even when a 

 large number ai"e present the nourishment of the cattle is not disturbed. Tliickening 

 of the gall ducts, so that a so-called "Medusa's head " forms on the surface of the liver 

 toward the stomach, appears in even well-nourislied animals; even in cases of a 

 cirrhosis of the liver it is seldom that any effect upon the cattle's health can be noticed, 

 and so long as a portion of the liver tissue about t^\ice the size of the fist remains intact, 

 the nourishment of the animal may be comparatively good. It is rare that one sees a 



