[theBCnut]

If they were struvite crystals, then it’s likely that the infection caused them and clearing up the infection is the most important thing. Adding D-mannose to the diet causes e. coli to let go of the bladder walls, so if it’s an e. coli infection that would help. In the short term, I would stick with the prescription diet, but if it doesn’t help, be ready to try something else. As everyone has said, do everything you can to make sure your dog is getting plenty of water.