Some months ago William went through a phase of needing to pee a bit more frequently and needing to go urgently, so I took him and a pee sample to the vet. She did a dipstick test and it showed an infection so he was put on antibiotics, which resolved the problem.
She also said he had traces of crystals (can't remember which sort) and wanted to sell me a particular kibble. As William is raw fed I declined! He's never been one for drinking lots of water and he doesn't cock his leg and mark but tends to go for hours and hours in between pees. So his urine often looks quite yellow and smells a bit strong - like human urine does when someone is dehydrated.
So I started adding filtered water to his breakfast to make sure he has quite a lot of moisture (raw food + water) early on in the day and monitored his drinking habits. For my own satisfaction I then got the vet to do a full urine analysis, not just a dipstick test, a couple of months later, and it came back normal.
I've continued adding filtered water to his breakfast every day. I think it benefits him. I remember when I was a child my mother was always nagging me because I hardly drank anything. I used to get dreadful headaches and ended up with a nasty kidney infection when I was 10, triggered by dehydration, so I know it can cause problems.
I think if Ben was mine I'd take him and a pee sample to the vet and ask her to have a feel of his prostate as well - typical old man problems, but best checked I think.