Priapism is a persistent erection without sexual stimulation and is diagnosed by physical examination. Partial paraphimosis can also result. Priapism can be caused by myelopathy, drugs, vascular abnormalities, penile masses, trauma, castration in cats, or it can be idiopathic. It can be ischemic and a medical emergency. If nonischemic and no primary cause is identified, therapy with gabapentin, ephedrine, or terbutaline can be attempted. Castration is not helpful, because priapism is not testosterone mediated.
If necrosis or gangrene is severe, amputation of the penis and prepuce and urethrostomy might be necessary.