504 POULTRY DISEASES AND PARASITES 



The following pages are given over, with a few exceptions, 

 to methods of preventing the further spread of disease which 

 has actually gained entrance to the flock and to the control 

 of both internal and external parasites. No pretension is 

 made at a critical discussion of these diseases, nor do those 

 discussed by any means exhaust the list of ills to which fowls 

 are heir. Only those rather frequently found on general farms 

 are referred to. For a rather complete and critical discussion, 

 students are referred to Diseases of I'oiiUnj by Pearl, Surface, 

 and Curtis, which is the most satisfactory work so far 

 published. 



Aspergillosis. — Aspergillosis is a disease that is very 

 generally confused with tuberculosis because the general 

 symptoms are so similar, though caused by a fungus growth on 

 the interior of the air passages. It is usually impossible to 

 distinguish between it and tuberculosis during life. On 

 postmortem examination red patches of fine mould will be 

 foimd on the interior of the air passages instead of the 

 characteristic lesions of tuberculosis. The origin of this 

 trouble is the presence of the mould, or its spores, in the 

 feed, litter, or surroundings of the birds affected. So far 

 as is Ivnown, there is no cure. Where postmortem examina- 

 tion has disclosed the presence of the disease in a flock 

 steps should at once be taken to remove the cause through 

 disinfecting the house, providing sweet, clean litter, and 

 avoiding all feed that is musty or mouldy. Any further 

 birds giving evidence of lack of thrift should be isolated, 

 and if they continue to lose strength should be killed and 

 burned on the assumption that they have contracted the 

 disease. 



Blackhead. — For a discussion of this disease see page 425. 



Bumble Foot.— This name is given to an abscess in the ball 

 of the foot or between the toes. It may be the result of a 

 bruise or the penetration of a thorn, or even a piece of straw. 

 It will usually be first noticed through the lameness of the 

 bird. Recovery frequently takes place without treatment, 

 hut it is best to catch the affected individual and pull out 

 the one or more pus cores that are generally present. These 

 cores are each covered with a scab, and may usually be 



