Prolapsed phallus can sometimes occur in male ducks and can be trauma-induced or a clinical sign related to venereal disease. A prolapsed phallus is described as a condition in which a male duck's phallus (penis) remains outside of the body and is unable to retract back inside the body. The longer the phallus remains outside of the duck's body, the greater the risk of secondary bacterial contamination and damage to this important body part. When the phallus is outside of the body, it runs the risk of becoming enlarged and swollen, dry and ulcerating, and necrotic during advanced stages. The duck is usually acting abnormal and may appear depressed, isolate themselves, and show no desire to eat, mate, or socialize with other ducks.
Prolapsed phallus is also a clinical sign that is often seen in ducks with duck plague