Peeing less?

For the last 2-3 days, Dexter's only been peeing once, maaaaaybe twice a day. He's been drinking just fine, he always has water available to him (except at night). He's pooping fine, and he's acting fine, and eating fine, so I'm tentatively ruling out kidney failure :?

I haven't had a dog since I was a child, so I don't remember peeing frequency...but do you guys think Dexter's OK? Is he just maturing? Is 1-2 pee sessions a day normal? He's 10 months old tomorrow.