Litter training older bunny

Question
Hello!
A few months ago I wrote to you about my 8 year old rabbit who refused to eat pellets due to different taste of the same brand. This has been resolved, I think he started eating them a day or two after I wrote to you.
But he's been having problems with using litter for almost two years now. When it started, he would still use his litter box regularly and occasionally he would urinate in a random place outside of it. At that time vet discovered he had a benign tumour on one of his testicles so he was neutered, but the problem persisted. He was checked (due to other issues as well) for kidney problems and it seemed his kidneys were failing. Now, 2 years on, the latest blood test revealed that his kidneys actually improved and should be working normally. Vet also checked his urine and all seems normal. But his litter problem is worst than ever. He doesn't use his litter box at all and he has no set place - he urinates where ever he feels the urge to. He sometimes urinates even right where he sleeps. He is free roaming, his litter box is on the ground with one side lowered so he can just step inside it. I've been using same pellet/hay lining throughout all those years. He likes to sit in his litter box, he just doesn't use it for urinating anymore. When I catch him urinating I put him gently inside his litter box, but he jumps out and goes sulking and urinating under the bed. I tried using several litter boxes scattered throughout the room but he would consistently urinate anywhere but inside one of them - quite often right beside them. Do you have and idea what else I could try?
Thank you in advance for your answer!
Dora

Answer
Hi,

we have one guy sort of like yours.  the one thing I can suggest is putting towels around the litterpans in order to catch some of the peeing around the boxes.  The other thing is to put towels in the places he seems to go the most in order to catch his urinating most of the time.  Easily washable but they will be dedicated bunny towels.