If an egg remains in the oviduct for an abnormal length of time, a number of problems may result. These problems tend to be most severe in the smaller species. If an egg remains lodged in the pelvic canal, it can interfere with blood circulation in the pelvis and to the kidneys. The egg can interfere with urination and defecation, leading to metabolic disturbances. The egg can press against the wall of the oviduct, causing it to die and rupture.
Clinical Signs Presenting clinical signs vary with the individual bird.
A hen may appear depressed, have an abnormally wide stance, and make repeated straining motions. Some birds may be puffed yet perching, while others may be found on the bottom of the cage. Some birds may even be found dead on the floor of the cage or aviary without any previous warning. Droppings may be larger than normal or no droppings may be passed and the vent may be dilated and swollen. Many birds have a history of prolonged egg laying, while others may have never laid an egg before.