We went through something VERY similar with our yorkie-poo Brody when he was about 7yrs old. He was acting weird, sleeping more often when he'd usually act like a puppy still. Then when he'd go outside he seemed like he was straining. Most of the time he'd produce no urine but sometimes only tiny tiny drops would come out. We took him to an emergency vet since it was on a weekend and our regular vet was closed. They did an x-ray and with what little urine he produced they took a sample as well and also didn't see crystals. However, the x-ray showed he had bladder stones and it was blocking his urethra. They told us that and told us we "should" follow-up with his regular vet the next Monday. When we explained it to his vet, she seemed alarmed that the vet we took him to didn't catheterize him IMMEDIATELY and told us to bring him in ASAP. She performed surgery the same day and told us that he could've died if we would've waited. None the less we were VERY unpleased with that ER vet...
I know you didn't mention if an x-ray was done but if it were me I'd make sure he gets one to check for stones. Bacteria can build up very quick and also tell the vet he should be catheterized.
Don't mean to worry you... I know everyone's experiences are different but that was mine and I hope it helps!
Happy 1st Birthday Rocco!
You little cutie!
