Urine Calcium in urine

I've noticed my pig (not sure which) has had some calcium in their urine. Not a lot, just a couple spots of white on the fleece. It's not a constant thing. I think the problem was that I accidentally fed my pigs spinach and then romaine two days in a row. It appeared after that. I normally space it out more. I have cut out the green leafy veggies for now to see if the issue clears up. Is calcium in the urine an automatic call for a vet visit? He is acting totally normal. Eating fine and playing. There is no blood in the urine either. Is it safe to wait a couple more days to see if it clears up?