Kimmy,
First, let me offer my prayers to Logan to get through this! At the vet is the best place he can be right now.

I went through this with Dakky, nearly exactly one year ago. I knew, knew, KNEW something was wrong the minute I walked in the door, and we rushed to the ER vet. They nearly sent us home that night, and sadly, Dakky would have died. Daks was completely blocked, and though they unblocked him, he blocked again. It was a total stroke of luck that the vet did an ultra sound and discovered the crystals. I can't tell you how many times I thanked God that for whatever reason, I asked for a scan.

Daks had the surgery (PU), and it was a success. I still watch him like a hawk, and he does have some "dribbles" from time to time. He is on CD only, and I put some wet CD and water down every day to increase his liquid- which is key.

I would really encouage you to keep a hawk-eye on Logan, and don't delay a return trip.

Good luck, and keep the updates coming.
Johanna