Paraphimosis, the inability to completely reduce the penis into the preputial cavity, most commonly occurs in a dog after manual semen collection, less commonly after coitus. The skin at the preputial orifice becomes inverted, trapping the extruded penis and impairing venous drainage. Other causes of paraphimosis include a small preputial opening, priapism, foreign objects around the penis, a constricting band of hair at the preputial orifice (feline), or trauma. Paraphimosis is easily differentiated from priapism (persistent erection without sexual stimulation), a congenitally short prepuce with secondary penile exposure, penile neoplasia, or a penile hematoma on the basis of physical examination.
Paraphimosis warrants veterinary intervention if not resolved quickly. The exposed penis quickly becomes edematous, because its venous drainage is compromised. With continued exposure, the mucosa becomes dry and painful. Self-trauma exacerbates the condition. If recognized early, before severe edema and pain develop, paraphimosis is easily treated. Treatment begins with gentle cleansing and liberal lubrication of the exposed penis. The penis is then replaced inside the prepuce by first sliding the prepuce in a posterior direction, extruding the penis further. This everts the skin at the preputial orifice; usually the prepuce then slides easily over the penis. The edema resolves promptly once circulation is restored. Hypertonic solutions (sugar) can be useful in difficult cases. If the everted prepuce does not slide over the edematous, exposed penis, a cold compress may be applied with gentle digital pressure to act as a pressure bandage. A temporary purse string suture can be placed to keep the penis inside the prepuce.
With paraphimosis due to other causes, or of longer duration, sedation or general anesthesia can be required. It may be necessary to incise the preputial skin to thoroughly examine the preputial cavity, remove restricting material, and relieve venous obstruction. The penis is then replaced in the preputial cavity, and the incision is closed. If the urethra has been damaged, temporary placement of a closed-system indwelling urinary catheter may be needed to prevent stricture formation. Chronic cases may require preputial orifice revision or advancement.