Seeking advice from anyone with a male cat who can't be neutered.

I adopted a cat in 2024 and he's a sweet little baby. He was born with one kidney and has cholangiohepatitis, which is treated by a specialty veterinarian. We went to get his neuter when he was of age and were told they could only find one testicle, despite cutting into his abdomen to try and find it. The "missing" testicle was on the same side that he did not grow a kidney, so the assumption was it must not have grown due to his anatomical anomalies. As he got older we noticed he was displaying symptoms of an unneutered male cat so we went back to the vet for another opinion. We were referred to the University of Minnesota Veterinary Clinic for a consult on this issue and further treatment for his liver.

At the U of M hospital we had them do x-rays, CT scans, and ultra-sounds to see if we could find any remaining tissue that would be obvious we could remove. We were unable to find anything through scans and his bloodwork values clearly showed testosterone levels were very high. We agreed to an exploratory surgery and they were able to find a small piece of tissue thought to be testicular growth and the lab result did return positive. We thought we were finally in the clear. His behavior did improve for about 2 months and has since come back stronger than ever. We've had UAs done every few months and they come back normal, and is checked for possible UTIs when we see our vet and that is always normal.

We're still dealing with marking everywhere. Beds, furniture, pillows, computers, doorways, clothes, their toy bin, basically nothing seems to be off limits. He originally started marking by fully squatting and peeing on a flat surface, but a few months ago he figured out he can stand and spray things instead. The next step we thought to take was to hire a behavioralist to come look at our home and consult with us about his environment to see if there are contributing factors we can't see. We do have a female cat, whom is his littermate and she is spayed and they're bonded so that doesn't seem to be an issue. I know people have unneutered male cats and I imagine they're not constantly running around their house cleaning up urine but I could be wrong. I wanted to see if anyone has delt with this or has ideas for us outside of what we've already tried.

Things we've done:

• Added multiple litterboxes - covered and not covered for options
• Used different diffusers around the house
• Use enzyme cleaners on all surfaces
• Use an enzyme laundry add on to help remove scent from washable surfaces
• Provide playtime throughout the day physically with us and with mentally stimulating toys
• Frequently clean around doors and windows incase he can smell other cats somehow
• We do not yell or scold him, just silently redirect if we catch him
• Calming treats
• Medication through his veterinarian

He does use litterboxes, so this marking is in addition to that. It seems to happen more frequently overnight or in a room we happen to be in. He typically gives a warning sign of yawling before he does it but doesn't strain at all when he is urinating. Nor does he seem physically uncomfortable doing it. I'm just at a loss of where to go from here, but this seems almost entirely behavioral from what I can tell.

Poster Age: 37F

Country: United States

Vet info: Yes, we regularly see a primary and specialty vet.

Main Issue: Cat has anatomical abnormalities preventing us from fully neutering him. We are trying to resolve behaviors of marking around our house as much as possible to make him comfortable and so he stops destroying our belongings.

Cat Age: 2 years old

Cat Sex + neuter info: Male - unneutered

Financial situation: Yes, and have insurance