Chicken Cholera. Fowl Cholera. Chicken Typhoid, etc. 161 



cholera, typhoid fever and other affections in which the virus 

 abounds in the alvine discharges. The sale and transportation of 

 the guano from the infected poultry yard is a direct cause of new 

 outbreaks. Feeding ou the carcasses or offal of the infected birds 

 is a further cause. It must not be forgotten that the microbe is 

 largely saprophytic, living indefinitely in the organic matter in 

 soils, and determining new outbreaks when brought in contact 

 with susceptible animals. Thus a period of immunity may be 

 followed by infection when new birds are brought in or when 

 young and susceptible ones grow up. 



Susceptible Animals. Fowl cholera is preeminently a disease 

 of chickens, but the microbe is successfully transferred to pigeons, 

 peafowl, pheasants, parrots, ducks, canaries, sparrows and other 

 small birds, also to Guinea pigs, rabbits, white and gray mice. 

 Guinea pigs have abcesses in the seats of inoculation (Pasteur); 

 the same is alleged of sheep and horses (Kitt), and man (Mar- 

 chiafava, Celli). Injection into a cow's teat caused chronic 

 catarrhal mammitis in which the microbe persisted for a long 

 while (Kitt). Like other members of the group of microbes 

 causing septicaemia hemorrhagica, the pathogeny and even the 

 morphology are liable to material modification as grown in 

 different environment (genera). Some of the forms of cholera 

 occurring among domesticated birds and held to be distinct dis- 

 eases may find in this an explanation. Rabieaux claims that 

 under favorable conditions it has been transmitted to the frog. 



Incubation . This varies from 1 8 to 48 hours, the usual being 

 24 hours. 



Symptoms. In some fulminant cases the animal is found dead 

 a few hours after apparently blooming health ; it may even have 

 died on the nest or fallen dead from the roost. Cadeac speaks of 

 transient symptoms even in such cases — extreme dulness, pros- 

 tration, somnolence, seclusion in a cool, dark place, ruffling of 

 feathers, sinking of the head between the wings, drooping, trail- 

 ing wings and tail, violet comb, gaping, discharge of glairy 

 mucus from the bill, convulsions and death. These symptoms 

 last from two to five hours. 



In acute but less fulminant forms there is loss of appetite, de- 

 pression, debility, apathy, erection of the feathers, sinking of 

 the head, swaying when made to walk, drooping wings and tail, 

 1 1 



