302 



DISEASES OF THE LIVER. 



animals, being well nourished and fat, are able to resist the first attacks 

 of the parasite, so that even an observant shepherd only notices a little 

 dulness, want of condition, and muscular weakness. It requires a care- 

 fully trained eye to note these very general symptoms, for the bodily 

 condition only changes very slowly and progressively, the appetite remain- 

 ing good. Experienced butchers, however, in the districts where disto- 

 matosis is common, readily detect this condition. The animals make 

 little resistance when handled. 



Nevertheless, even in this primary phase, the conditions are not always 





C — 



Fig. 158. — Drawing from a microscopic preparation showing a, fluke in the tissue of 

 the Hver. «, Necrotic Hver tissue; b, atrophic hver cells; c, spines on the fluke, 

 showing the outline of the body. (After Schaper, 1890, PI. III., Fig. 5.) 



as above sketched, and a certain number of deaths may occur. Gerlach 

 has mentioned the possibility of death by cerebral apoplexy, in conse- 

 quence of the young distomata penetrating to the brain. Moussu has 

 certainly never seen such a complication, but has seen death from 

 hepatitis, perihepatitis, and secondary pericarditis in animals gravely 

 infested. The young embryos, whether they penetrate only by the bile 

 ducts, as has been stated, or are carried to the liver by the blood stream, 

 often excavate canals in the substance of the gland before establishing 

 themselves in the bile ducts. They make their way as far as Glisson's 

 capsule, and may even penetrate it; and as they carry with them innumer- 

 able intestinal germs, when they arrive rid the bile ducts, they set up 



