218 



POULTRY DISEASES 



likely to be some deformity. Curvatures of the spine have 

 been noted to appear suddenly in young, developing birds. 



Injury to the Spine. — Often, large animals, step upon or 

 knock over fowls in walking. This may result in broken ])ones, 

 internal hemorrhage as a result of crushing, and injury to the 

 spine or other parts. 



GANGRENE 



There are two kinds of gangrene, moist and dry. Death of 

 a part en masse constitutes gangrene and death cell by cell on 



a surface constitutes ulcer- 

 ation. If the part which 

 dies has poured out in it 

 much serum, there is likely 

 to result infection and ne- 

 crosis with gas formation. 

 This gas is very offensive. 

 If the part is poorly sup- 

 plied with blood and there 

 is no serum secreted there 

 may be a dry gangrene ; 

 that is, the part mummi- 

 fies, does not give off an 

 offensive odor and becomes 

 dry and hard. Dry gan- 

 grene is likely to occur in 

 dependent parts, as in the 

 illustration, in the foot of 

 a turkey. 



FROZEN COMBS 



The degree of cold at 

 which the wattles and comb 

 freeze depends upon many 

 factors. The humidity in 

 the house and the physical 

 condition of the bird and 

 its heart action are the 

 most important factors. A 

 weak heart means a slug- 

 gisli circulation and the 

 more sluggishly the blood flows the slower it passes througli 

 the dependent parts and tlie quicker the comb freezes. 



Wattles usually freeze sooner than combs because when tlie 

 l)ird drinks it usually gets its wattles wet. 



Birds in open front houses can stand lower temperatures 



Fig. 78. Gangrene of the Foot of a 

 Turkey. 



Commenced with fluctuating abscesses be- 

 tween the toes which when lanced gave off 

 an offensive cdor and seemed somewhat 

 gaseous. Later the parts became in a state 

 of dry gangrene. A smear from the pus 

 showed many eosinophiles, lymphocytes and 

 polymorph olcukocytes. 



