Mice are cute and fun little animals to keep as pets. If you have a male mouse, though, he may develop a penile prolapse (‘paraphimosis’), a condition in which his penis no longer retracts back into the prepuce (the foreskin covering the penis). [1] A penile prolapse is unsightly, of course, but is also very uncomfortable for your mouse and can lead to serious health problems. The earlier you recognize and treat the prolapse, the more quickly your mouse can heal and get back to his normal activities.

After your mouse has gone through intensive veterinary care, you will need to take good care of him at home. For example, you will need to keep the surgical area clean—your veterinarian can provide you with instructions on how to do this. In addition, put clean white towels in his cage where he can lie without the risk of getting bedding near the incision site.

If your mouse’s case of penile prolapse is particularly extreme, or the penile prolapse keeps occuring, your veterinarian may recommend surgery to enlarge the opening of the prepuce. With your mouse under anesthesia, your veterinarian would apply a local anesthetic to the surgical area before enlarging the opening.

If your mouse has a severe case of penile prolapse, or your treatment attempt was not successful, he will need further treatment by your veterinarian. One treatment method your veterinarian may want to use is the puncture technique, during which he or she would use a hypodermic needle to create tiny puncture holes in the prepuce to release the fluid causing the swelling.

If you were able to reinsert the penis, observe your mouse to see how well he is recovering. Watch to see if the penis prolapses again, and take note of any bleeding or discharge you see from the penis or prepuce. Continue to monitor your mouse’s urination, and look for blood in the urine.

With the penis sufficiently lubricated, pull it out a little bit further (if possible) and lubricate the shaft of the penis. With your thumb and index finger, gently push the penis back down into the prepuce.Contact your veterinarian if you are not successful with reinserting the penis.

Putting oil on your mouse’s penis could get a little messy, so apply the oil with some gauze or cotton balls. The lubrication will make it easier for you to manually reinsert the penis back into the prepuce.You do not have to use a lot of oil.

If the penis is swollen, you will need to reduce the swelling so the penis can slide back more easily into the prepuce. One way to reduce the swelling is to sprinkle some granulated sugar on the penis and surrounding area. The sugar pulls in the fluid from the prepuce and penis, thus reducing the swelling in both structures.

Dampen some gauze or cotton balls with your cleaning solution of choice and gently clean your mouse’s penis. Be careful to remove any debris that may have gotten stuck on the penis. When you have finished cleaning, pat the area dry with another piece of gauze or a clean towel.

It will be easier to access your mouse’s penis by placing him on his back. To put him on his back, hold the base of his tail in your dominant hand and place your thumb and index finger of your non-dominant hand just behind your mouse’s front legs. Gently squeeze together the skin behind his ears to scruff him and turn him on his back.

To get your mouse out of his cage, gently grasp the base of his tail and let him walk into your cupped hand in the bottom of his cage.You can let go of his tail when he is comfortably settled into your hand.When you grasp his tail, make sure he is not holding onto anything—his tight grip could cause you to injure him by pulling the skin off his tail.You definitely do not want to make him feel any more pain of discomfort!

To treat your mouse’s penile prolapse at home, you will need some supplies to clean, disinfect, and treat the affected area. For cleaning, you will need a handful of sterile 2 x 2 gauze or cotton balls, as well as some warm water and mild soap.Instead of soap and water, you can use saline as a cleaning agent.

If your mouse has a mild case of penile prolapse (mild inflammation, little to no pain), you can treat him at home with noninvasive treatments. More severe cases, however, will require invasive veterinary care. In severe cases of penile prolapse, the penis has become infected (yellow discharge) and significantly enlarged with fluid. Some of the penile tissue may have also died due to no blood flow.

A penile prolapse can make it difficult for your mouse to urinate.This is because the urethra, which carries urine out of the body, can become blocked with a penile prolapse.Check the cage bedding periodically to see if your mouse is urinating. You can also put a towel in his cage to see the urine more easily.

A penile prolapse is easy to recognize. Your mouse’s penis will be outside of the prepuce and dragging along the cage floor.It will also be swollen,red,and possibly dry and bleeding. You may also see a swollen band of the prepuce behind the head of the penis.

Take your mouse to your veterinarian if you are not comfortable with treating your mouse’s penile prolapse on your own. If your own veterinarian does not have a lot of experience treating mice, ask him or her to recommend an experienced exotic veterinarian in your area.

Sometimes, the prolapse can be so severe that the penis cannot retract back into the prepuce, even after the inflammation has been treated.You may need to consider euthanizing your mouse if his penile prolapse cannot be successfully treated.

If your mouse has cage mates, they may bite the prolapsed penis. They may even bother the surgical area after your mouse has been treated. Consider separating your mouse from his cage mates if he has a prolapse.

This article was co-authored by Pippa Elliott, MRCVS . Dr. Elliott is a veterinarian with over thirty years of experience. She graduated from the University of Glasgow in 1987, and worked as a veterinary surgeon for 7 years. Afterward, Dr. Elliott worked as a veterinarian at an animal clinic for over a decade.

If you have a male mouse with penile prolapse, a condition in which its penis doesn’t retract, monitor the mouse to be sure he is still urinating regularly. If the mouse isn’t urinating, or if its penis is significantly enlarged or has a yellowish discharge, take it to the vet immediately. If the penile prolapse is less severe, gently place the mouse on its back on a clean towel and disinfect the penis, then apply granulated sugar to the area to help reduce the swelling. Once the swelling goes down, lubricate the penis with a little olive oil and slide it into the foreskin.