130 Diseases of Poultry 



The above recommendations, while drastic, will probably 

 prove the wisest in the long run. There are, however, some- 

 times mitigating circumstances under which it would not be 

 advisable to do this. If it is known that the disease has 

 recently been introduced or that it is not very widely spread 

 through the flock all of the old stock should be removed and 

 killed for table purposes, providing their condition permits. 

 Van Es and Schalk have shown that it is the older birds that 

 furnish the higher percentage of actual disease. Their 

 autopsy records show the following : 



Age op Bird 



Per Cent op Infected Birds 



3.33 

 24.35 

 86.44 

 85.71 



Van Es and Schalk recommend that "After the elimina- 

 tion of the older birds the remainder of the flock may be 

 tuberculin tested and all fowls reacting typically or doubt- 

 fully should share the same fate as the older birds." 



After the diseased birds have been disposed of the houses, 

 runs, eating and drinking utensils should be thoroughly 

 cleaned and disinfected. Everything loose should be burned. 

 The disinfecting so far as possible should be done by boiling 

 and by sunlight. IVIost of the common disinfectants cannot 

 be relied upon to kill the tubercle bacilli. Heat and sun- 

 light are very eftective wherever they can be applied directly. 

 The runs should be cultivated and the houses should be 

 open to the sunshine and fresh air at all times. 



Van Es and Schalk report a flock which at the beginning of 

 1913 had 249 chickens. Of these 43.37 per cent were found to 

 be tuberculous by the tuberculin test and autopsy. All react- 



