214 



PARASITES OF THE DOMESTIC ANIMALS 



soinewhiit compact, and arc iicucrally little adherent to the wall of the 

 hydatid. 



Old h>'datids iua>' beeoiue considerably modified or completely 

 destroyed. In such cases the walls are much thickened and show 

 degenerative changes. The fluid diminishes and disappears with the 

 contraction of the cavity, the degenerative material in the walls he- 

 comes more dense, there is calcareous infiltration, and, finally, the 

 hydatid may he transformed into a calcareous mass. 



Symptoms. — The symptoms of hepatic echinococcosis in lower 

 animals arc, as a rule, too vague for recognition of the specific affection; 



Fig. lis. — Echinocoocus granulosus, with fibrous sac laid back, sliowing hydatid 

 with brood capsules (after Leuckart) . 



it usuaUy remains for post-mortem examination to estalilish the diagno- 

 sis. Pulmonaiy echinococcosis is generally accompanied l).y the hepatic 

 form, and may exhibit respiratory disturbances, as accelerated respira- 

 tion and dyspnoea, — .symptoms which may be contributed to by j^ressure 

 of the enlarged liver upon the diaphragm. In the region invaded l)y the 

 hydatid the vesicular murmur is lessened or wanting, while in parts 

 nearby it is increased. Percussion will generallj' definitely- establish 

 its location. 



Hydatid disease rarely progresses to a fatal termination in lower 

 animals. 



Control. — As the tapeworm from which the echinococcus is derived 



