130 



VETERINARY PATHOLOGY. 



In some rare instances it appears that an embolus travels 

 in the direction opposite to the flow of blood and produces 

 obstruction ; this is called retrograde embolism. 



Effect. — The results of embolism depend upon the composi- 

 tion of the embolus, obstructed circulation and infarction. 





of' ' k 



v-p>x* v6 .^ ^: ' ^■'■'"' 



1 * "^t 'till 



r". 







Vi'j; xr, — Aneniif infarcts in thr spleen, 

 a. Tnfarcted areas (Uu- to emljcill in cajjillaries supplying them. 



Coiiip'Osifion of the cmboliis. — Emboli composed of cells 

 ha\ing the power to multiply, at the point of impaction (embol- 

 ism) become secr)ndarv foci or metastases of the primary patho- 

 logical condition, as metastatic sarcomata, leukemic infarctions, 

 etc. Pathogenic bacterial emboli not only obstruct circulation, 

 but also produce metastases of that disease as in necrobacillosis, 

 anthrax, etc. Filarial emboli and emboli composed of fatty cells 

 produce a mechanical effect only. Air emboli in small vessels 

 are absorljcd after a time. 



