108 POULTRY DISEASES 



great. The disease spreads rapidly through a flock. Pure- 

 bred birds are more susceptible than scrubs. In an outbreak 

 of cholera among ducks, studied in the author's laboratory, 

 the disease progressed very slowly. Only one to five or six 

 ducks died in the course of a week in the flock of 500. 



Postmortem Findings. — Upon opening the abdominal cavity 

 one will first note that the liver is greatly enlarged, very dark 

 in color and tears easily (inflammation, congestion and cloudy 

 swelling) ; we have found livers that weighed as much as 120 

 grams, or three times the normal weight. The intestines are 

 congested and contain a frothy material, dark in color. There 

 is an occasional hemorrhage in the lining {mucosa) of the 

 intestines. The spleen may be enlarged and its contents soft. 

 Small hemorrhages {petechiae) may be found in the heart, its 

 coverings and other parts. The kidneys are dark, enlarged 

 and soft (active and passive congestion and cloudy swelling). 

 The blood does not coagulate readily and is found, upon micro- 

 scopic examination, to be teeming with the germs causing the 

 disease (Bacillus avisepticus) . 



There is acute hemorragie inflammation in the intestines 

 and lungs in association with small hemorrhages on the 

 serous membranes and sometimes a fibrinous exudate of the 

 pericardium and other serous membranes. Some of the blood 

 vessels covering the intestines are injected and the intestinal 

 contents, always in a fluid condition, may be mixed with blood. 

 The mucous lining of the intestines is reddened, particularly 

 in the first portion. 



The lungs may be congested and edematous and at times 

 contain areas of croupous hemorrhagic pneumonia. There 

 may be a fibrinous pleuritis. There is a catarrhal inflamma- 

 tion of the upper air passages. 



Case Report on Fowl Cholera 



A dead duck was sent to the laboratory from the outbreak 

 referred to above. The anatomical lesions found in the carcass were 

 as follows: Hemorrhagic areas in heart and epicardium; inflamma- 

 tion and congestion of the ceca, and congestion of the other por- 

 tions of the intestines; the liver enlarged, weighing eighty grams, 

 and very dark in color. 



Two glycerin agar slants were inoculated from the heart blood 

 and from the liver. Stained smears from the heart blood showed 

 the typical polar-staining Bacillus avisepticus. Pure cultures were 

 obtained from the inoculated tubes. A pullet weighing two pounds 

 was given an intraperitoneal injection of ihe twenty-four-hour agar- 

 slant growth. Twenty-four hours later she appeared sick, showing 

 ruffled feathers, loss of appetite, dullness, head and tail down and 

 temperature 108.2 degrees Farenheit. 



An examination of the blood revealed the following: Hemoglobin. 

 90 per cent; erythrocytes, 2,520,000; leukocytes, 6,000 (hypoleuko- 



