742 IOWA DEPARTMENT OP AGRICULTURE 



ration, and by giving an occasional purgative, such as Epsom salts or 

 castor oil. In any event the food must be abundant, the fowls must have 

 plenty of exercise, and the houses must be kept in a dry and sanitary 

 condition. 



INFECTIOUS DISEASES OF YOUNG CHICKS. 



Young chicks are particularly susceptible to the attacks of the various 

 microbes which cause disease in adult fowls, and the conditions of in- 

 fection, the symptoms, and the preventive measures to be adopted vary 

 to such an extent that they must be given special consideration. 



White Diarrhea. — This is a condition which has as its most promi- 

 nent symptom more or less profuse diarrhea, the droppings consisting 

 almost entirely of mucus from the intestinal tube and the white secretion 

 of the kidneys. The diarrhea results from irritation of the intestines and 

 of the increased secretion of mucus, while the large quantity of white mate- 

 the increased secretion of mucus, while the large quantity of white mate- 

 rial secreted by the kidneys is due to fever and rapid breaking down of 

 the elements of the tissues. This condition is most frequently seen with 

 incubator chicks, but is also common with those which are hatched 

 under hens. 



Causation. — It has been found by investigation that the white diar- 

 rhea of young chicks is caused by at least four different kinds of infec- 

 tion, and each of these needs to be studied separately. All of these mi- 

 crobes also infect adult fowls and are generally communicated directly 

 or indirectly from these^to the chicks. 



The most common cause of the disease is a bacillus called Bacterium 

 pullorum. This often infects hens and also the eggs which they lay. 

 Such eggs produce chicks which have the germs of the disease within 

 them when they are hatched, and these chicks show symptoms within 

 the first few days of their lives. The contagion may also be communi- 

 cated from chick to chick by means of the microbes scattered with the 

 droppings, which contaminate the food and drink, and cause the appear- 

 ance of the symptoms when the birds are from 1 to 2 weeks old. The 

 chicks are most susceptible to infection during the first 24 hours of their 

 lives, are more resistant during the second and third days, and are 

 practically insusceptible after the fourth day. Those that sicken later 

 must have taken the microbas into their bodies before they reached that 

 age. Incubators and brooders, as well as coops, become infected and 

 preserve the contagion indefinitely. Adult fowls are resistant to the 

 microbe and do not show any symptoms even when they are laying in- 

 fected eggs. 



The cholera bacillus may also be carried by laying hens and infect 

 the egg before it is laid. The young chicks hatched from such eggs soon 

 show symptoms of disease and communicate the contagion to others at 

 all ages. 



The coccidia which causes a chronic disease in adult fowls may also 

 infect the eggs and cause disease with similar symptoms in the chicks. 



The aspergillus fungus in the fourth cause of white diarrhea. It 

 occasionally is included in the egg when it is laid, but it may also pene- 



