[bildio]

I have a very similar problem with Gus. This has been going on since I got him in March of this year. His several urinalyses showed a low specific gravity which indicates that he is not concentrating his urine, however, his vet thinks he's okay.

After much frustration, and trying many things, I'm currently focusing on what he is eating. He loves to eat stuff from on top and under the ground outside, particularly tree bark, wood chips, worms, and insects. Since limiting this behavior to the extent practicable, without putting something over his snout, there is some improvement.

I also noticed that certain chew things, like Bully Sticks, Dingos, & DentaBone, trigger thirst, and with thirst comes drinking, and urination.

I was feeding him Science Diet for most of the time that we've been together, and am currently transitioning to something else to see if it helps.