My bun has had issues with calcium in his pee. I brought him into the vet and she gave him antibiotics and we just finished the bottle (vet instructed us to do so). He is still having the problem. I originally thought it was from the kale and I stopped feeding it but it hasn't cleared up a bit. He has a vet appointment in a few weeks to see if it has cleared up on the x ray. What is the cause of calcium sludge? What will happen if we don't find the cause and it's a problem he has his whole life? Does it hurt him?