264 Diseases of Poultry 



lapsed oviduct. If there is a mass of red or bloody tissue 

 projecting from the vent, one is safe in diagnosing prolapsus. 

 The only point which needs particular attention in the di- 

 agnosis is as to the degree to which prolapsus has occurred 

 when the bird is discovered. The importance of this lies 

 in the fact that on it depends the treatment which it is 

 advisable to give. Where the prolapse is only partial and 

 is discovered early it is advisable to treat it by the methods 

 outlined below. If, on the other hand, the prolapse is 

 extensive and has existed for some time before the bird is 

 seen so that the mass of tissue has turned a blue or purplish 

 color or has been pretty extensively picked and torn by the 

 other birds in the pen, then it is useless to carry on any treat- 

 ment and the proper thing to do is to kill the bird at once. 

 Etiology. — Prolapse of the oviduct may be caused by a 

 number of different things. It is observed not only in 

 old hens, but, in our experience, quite as frequently in 

 pullets. The fundamental cause of the condition is, of 

 course, a weakness of the oviduct walls and ligaments, 

 chiefly in respect to their muscular portions, which makes 

 the oviduct unable to stand the strains put upon it in egg 

 production. The immediate cause may be either : 



1. Straining to lay a very large (double yolked) egg. 

 This is perhaps the most common cause. 



2. Straining to lay when there is an obstruction in the 

 oviduct (egg bound). 



3. Constipation. The rectum full of hardened feces 

 stimulates all organs in that region of the body to expulsive 

 reflexes. 



4. Ziirn says that oftentimes feces may become lodged 

 in the cloaca in a sort of blind pocket, and then set up the 

 same expulsive reflexes as an egg in the cloacal or vaginal 

 regions normally does. In the effort to expel this foreign 

 body the oviduct may become everted. 



