PREVENTIVE MEDICINE 335 



generally shrivelling up in 3 to 4 weeks and dropping off. One 

 attack confers immunity which may last for several months. 



FOWL TYPHOID was recognised in Germany by Pfeiler* who first 

 described it in 1912. In an outbreak involving 87 fowls, of which 

 43 died or were killed when dying, Pfeiler isolated an organism 

 belonging to the typhoid group. A second outbreak occurred in 

 1915 in which the same type of organism was found, and the disease 

 was transmitted by means of cultures to fowls, pigeons and ducks. 

 Ducks and geese, however, do not appear to become infected in 

 natural outbreaks, whereas turkeys and guinea fowl do. 



PREVENTIVE MEASURES. Fowl cholera, fowl plague and fowl 

 typhoid call for similar measures for eradication. Once these 

 diseases are introduced they usually, of their own accord, cause the 

 death of most of the birds, but it is advisable to cut short outbreaks 

 by killing off the whole stock and by burning or deeply burying the 

 carcases in lime. An exception may only be made in the case of 

 very valuable birds which have not been exposed to infection. 

 These must be isolated on fresh ground until it is quite certain 

 they are free from disease. The place in which the birds have 

 been kept must be thoroughly disinfected, limewashed and left 

 vacant for a period before any others are introduced. Hen coops 

 and such like are best burnt and new ones provided. If disease 

 exists in the neighbourhood, any newly purchased stock should be 

 quarantined for a period to ensure that no infection be introduced. 

 The soil of the poultry yard should be turned up to a depth of 

 4 to 5 inches and mixed with fresh lime. 



In view of the milder nature of the other diseases described, 

 viz., avian diphtheria and epithelioma contagiosum, affected birds 

 need not be destroyed, but the stock may be divided into two 

 batches, viz. : (1) those apparently healthy and (2) those affected. 

 Any birds subsequently showing symptoms are moved to the 

 affected group. One need only destroy birds which are especially 

 badly affected. Disinfection must be practised and the usual 

 measures designed to prevent spread of the disease to healthy 

 poultry stocks must be put into operation. 



GAPES. 



Gapes of poultry is due to the presence of the nematode 

 Syngamus trachealis in the trachea and bronchi. Fowls and 

 turkeys and a large number of wild and game birds are attacked. 



Young birds are more susceptible than old ones, and a high 

 *Journ. Comp. Path., Vol. XXX., p. 263, Ref. 



