!14 



PARASITES OF THE DOMESTIC ANIMALS 



somewhat compact, and are generally little adherent to the wall of the 

 hj'-datid. 



Old liA'datids may become considerabty modified or completely 

 destro3'ed. 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 be- 

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

 h3'datid may be transformed into a calcareous mass. 



Symptoms. — The symptoms of hepatic echinococcosis in lower 

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



Fig. 118. — Echinococcus granulosus, with fibrous sac laid )Dacl<, showing 

 with brood capsules (after Leuckart). 



,-datid 



it usually remains for post-mortem examination to establish the diagno- 

 sis. Pulmonary echinococcosis is generally accompanied by the hepatic 

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

 tion and dyspnoea, — sjanptoms which may be contributed to by pressure 

 •of the enlarged liver upon the diaphragm. In the region invaded by tlie 

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

 nearby it is increased. Percussion will generally 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 



