Q: My gelding has been dropping his penis more than usual. I have had him checked by my vet, who sedated him, cleaned his sheath, and examined his penis. He found no obvious issues. My gelding has continued with this behavior even after being cleaned. Could this be a behavior issue related to him being turned out with my mare? They’ve only lived together for the past six months or so.
—Michelle, via e-mail
A: I wish I could get some video examples to see this behavior in context and give an opinion on whether what you are seeing is just a relaxed drop or an erection. That would help me form an opinion on whether it may be related to your mare. Because this dropping is not usual for him and having a mare companion is also new, sexual response to the mare certainly seems plausible. So it would be best to rule that in or out right away. Perhaps you could send video for an opinion on the sexual nature, or if you can remove the mare from your gelding’s turnout for a spell, you might be able to tell quite quickly if that was the stimulus.
There are some other situations that can be associated with an increased frequency of penis drop that are more worrisome and could benefit from a detailed veterinary evaluation. For example, certain diseases or injuries, or even some tranquilizers, can affect the nervous system control—specifically, the retractor penis muscles that hold the penis normally within the sheath. Also, urogenital discomfort (such as bladder stones, urinary tract infection, etc.) and sometimes chronic pain elsewhere