Many male lizards and some other reptiles like snakes have hemipenes. These little reproductive organs are all fine and dandy until one decides to pop out and then stay out, creating a painful-looking situation called a prolapse.
Understanding the Hemipenes
Hemipenes are moist, pink, fleshy, reproductive organs located just under and on either side of your male lizard's cloacal opening. Only males have them and they are not visible unless they are exposed. They are normally tucked away and appear as two small bulges underneath your lizard's cloaca at the base of the tail. This bulge along with the presence of large femoral pores are often the characteristics you would look for when determining if your lizard is a male.
Hemipenes are like miniature penises. They are little tubes used for mating but unlike humans, they are not used for urinating. They should not normally be exposed.
Why Would a Hemipene Be Exposed?
Sometimes hemipenes will come out if there are females in your male's line of sight or if your male feels another male is trying to be more dominant. One or both of his hemipenes may pop out and prolapse from these exposures to other lizards. Other times they will prolapse due to impaction, lack of humidity, or while purposely being sexed by a person ("popping" a hemipene is one way to sex some reptiles). Sometimes a hemipenis prolapses while removing excess skin and an impaction, and won't go back in.
Diagnosis and Treatment
If you see a pink bulge or two under the cloaca of your male reptile it probably has a prolapsed hemipenis. You can try applying firm but gentle pressure directly on the hemipenis with a moist cotton swab or your finger to retract it. If that doesn't work, try soaking the reptile in a warm bath with some sugar added or apply some honey directly to the hemipenis. These sweet techniques will help decrease the inflammation and hopefully make the hemipenis retract.
If a hemipenis comes out and stays out, it may also dry out. If you are unable to get the hemipenis to retract at home, keep it moist with warm water or apply some vaseline or another lubricant. Your exotics vet may have to anesthetize your reptile to retract the hemipenis, use a stitch to hold it in place, or even amputate it if it will not go back in and stay in. A hemipenis that stays out for too long can become infected. Therefore removing the prolapsed hemipenis is the best option to prevent a systemic infection from occurring.
Provide adequate humidity in your reptile's environment to assist in full body sheds and to prevent hemipenes and femoral pores from becoming impacted. Don't purposely extract the hemipenes to sex them or clean them. If you suspect the hemipenis is impacted, soak your reptile in a warm water bath for 15 to 20 minutes before trying to clean it out. If you are afraid the hemipenis won't go back in after it pops out to be cleaned, do not attempt it. Have your exotics vet handle it.
If other reptiles seem to encourage territorial behaviors and your males' hemipenes keep coming out, you should separate your reptiles and make sure they can't see each other from a different enclosure in the room.
Sometimes you can't prevent a prolapse but you can take all necessary precautions and be prepared if it does happen.