Urine smell stronger than ever

Question
Dear Tamarah,
My fancy mouse Edgar is 10 months old now. I try to avoid excess cleaning of his cage in order to not stress him. He has 2 cages, so I usually wipe the urine excess on his favorite "corners" and wheel while he's asleep on the other cage, twice or three times a week, and wash the cages thoroughly every 8~10 days, leaving some of the old bedding (aspen chips in one, ripped toilet paper in the other) and replacing the rest.
For a few days now, his urine has smelled a lot stronger than it used to. He has never mated, so I wonder if this could be a prostate condition (and is he too old to reproduce? I was thinking of getting him a girlfriend :), or just "overpeeing". He has been drinking more water than usual.
I was also wondering if my cleaning habits are appropriate: maybe washing should be more frequent? He's healthy, incredibly docile and very active, despite being a middle aged mousey.
One more thing (sorry for the huge question!): fancy mice are usually described as highly social. For lack of space and experience, I didn't get him a companion. I believe mice have distinct personalities, and being a single child never seemed to bother Edgar -- at the pet store he claimed the most isolated dome of the habitrail as his own, and would sleep and eat there alone while his brothers and sisters were all together, running away from the usual mice pile-ups -- and here he's the house sweetheart, everybody is always talking and playing with him. Still, now that I have more space and better knowledge, would it be better for him to have some company? I'm still uncertain on getting a female, as I can't take care of the entire litter, and probably wouldn't have the heart to sell them to pet stores (the one I bought Edgar from sells mice as food to snake owners :/). Introducing another male at this point would be a recipe for disaster?
Again, sorry for the huge question! And thank you very much for the initiative.

Answer
Hi Isabele,

It could be that he's trying to remark his favorite spots that you clean up, so before I worried about it I'd try going the full 8-10 days without spot cleaning for a couple of rounds and see if that reduces the smell a bit.  You can also try putting a small amount of natural vanilla extract in his drinking water (all you need is a drop or two, really, if you are using the small water bottles) to see if this will make his urine smell a little less strongly.  As far as what's causing it, if it isn't a matter of him just trying to re-mark his territory it could be indicative of a health problem such as kidney issues, but I definitely couldn't tell you for sure since I'm not a vet.  I would definitely assume bucky behavior first.

He is still breedable at this age, but if you aren't sure you will be able to handle the entire litter (and keep them separate afterwards, as leaving females with males all the time is stressful and dangerous to the female's health), I wouldn't risk getting him a girlfriend.  I definitely wouldn't try a male friend at this point, either, since even if they didn't hurt each other it would cause him a lot of stress (and make the cage that much stinkier - since it's linked to being territorial).  I think he'll be happiest just playing with people.  :)

Let me know if you have anymore questions!  :)
-Tam