92 Fowl Cholera. 



tion (Kitt, Ratz) is present in all the air cells and on all serous 

 membranes. 



In the less frequent chronic cases yellowish, grey, dry 

 caseous foci are frequently present in lungs, liver and on the 

 intestinal mucous membrane, sometimes also under the en- 

 docardium, which may become quite extensive, especially in the 

 lungs. Exceptionally even both lobes of the lungs may show 

 hepatization resembling caseous pneumonia (Jungklaus). At 

 the same time there may be a fibrinous pleurisy and pericarditis, 

 and in some of the joints and tendon sheaths a caseous exudate 

 may be present (Sticker, Hensel, Willach). 



In the acute form bacteria may be found in great numbers in 

 the blood, between the blood corpuscles and only sparingly in the white 

 blood corpuscles as well as in the exudates. The intestinal contents are 

 also virulent. In chronic cases the caseous foci also contain virulent 

 bipolar bacilli, while they are present in only small numbers in the 

 blood. 



Symptoms. Ostertag & Ackermann's experiments showed 

 the time of incubation after a single feeding with organs of 

 fowl affected with cholera to be 1 to 2 days in geese, and 4 

 to 9 days in chickens. After the recovery from a feeding in- 

 fection a new infection produced death in geese (feeding) as 

 early as 19 hours and in chickens (subcutaneous infection) as 

 early as 8 hours. The time of incubation is very likely the 

 same in natural infection. 



The acute form of the disease sometimes runs a very rapid 

 course ; the animals drop to the ground while running, or they 

 fall to the ground from an elevated place, such as the rod of a 

 cage, or from a tree, and die after flapping their wings a few 

 times. 



In the large majority of cases, however, conspicuous syrnp- 

 toms precede death. The birds suddenly become depressed, they 

 assume a crouching position, seek secluded places, and sit 

 trembling. Sometimes the head is hidden under the wing or 

 it may be turned backwards. The plumage is ruffled, the wings 

 may droop, and if they move a staggering and wabbling gait 

 is manifest with the winsrs hanging and the head drooped. 

 The appetite is impaired from the onset, while thirst, on the 

 other hand, is increased. A foamy slime drips from the nasal 

 and oral openings ; and from time to time the birds turn their 

 necks convulsively, or stretch out their heads on which the 

 bills, combs and wattles show a bluish-red discoloration. At 

 the same time they may vomit a greyish-yellow slimy mass. 

 At the height of the disease a profuse diarrhea develops; the 

 droppings are at first yellowish-grey, mushy in appearance, 

 later very fluid, dirty, greenish or reddish, mixed with coagu- 

 lated albumin-like flakes, and of a repulsive odor. The plumage 

 around the rectum becomes soiled and matted with the feces. 



The affected birds show difficult respiration which is mani- 



