130 DiSKASHS or POri.TKV. 



origans in the bird's body. It not only prepares the 

 bile, which is one of the principal digestive lifiuids, 

 l)nt it assists in st)ine of the most necessary chemical 

 changes which occur in the blood. This organ con- 

 tains numerous blood vessels through which passes a 

 very large quantity of blood, and it is particularly 

 subject to the attacks of various kinds of parasites. 

 Most of these parasites prol)ably find their way to the 

 liver through the l)lood channels, lodge in the minute 

 capillary vessels, and begin their multiplication and 

 disease -producing action. 



Among the parasites which most frequently affect 

 the liver of fowls are the chicken cholera bacteria, tl:e 

 tubercle 1)acillus, the protozoa of black-head (tur- 

 keys), and the aspergillosis fungus. These variously 

 cause congestion, inflammation, and death of the tis- 

 sue. 



The liver is very subject to congestion and this fre- 

 quently occurs from errors in feeding and as a result 

 of irritation in the neighboring intestines; it is, also, 

 frequently affected with atrophy and fatty degenera- 

 tion. 



CONGESTION OF THE LIVER. 



The liver of fowls is often found in a congested con- 

 dition as the result of lack of exercise combined with 

 over -feeding; also from the birds taking tainted or 

 moldy food or poisonous substances of various kinds 

 into their digestive organs; from the effects of infec- 

 tious diseases, particularly cholera ; and from obstruc- 

 tion to the circulation of blood l)y disease of the heart 

 or lungs. It is often seen in 1)irds which are in pleth- 

 oric condition or very fat. 



The symptoms are obscure and it is dif^cult to 

 make a diagnosis during the life of the affected bird. 



