Urinary calculi help please

Hello

I’m so upset and worried about my wethers. My lovely two year old boer wether had 11 stones blocking his urethra. Our local vet said to put him down but we took him to the large farm hospital. They immediately operated on him and placed a catheter in. After two weeks by some miracle he passed the stones.

I’m really worried I’ve caused the stones. I’ve always been anxious about the urinary calculi therefore non of my boys are on grain, our hay is only grass not alfalfa. There water is changed daily (warmed up in winter cooled in summer). When I have been visiting him at the hospital the vets said he seemed down could I bring him so treats. I took him broccoli and lettuce everyday for 4 days. The vets even fed him some of this in the mornings when he wouldn’t eat:

I picked him up today to take him home and met a vet I’d never met before. She made a passing comment not to feed him any calcium rich foods such as broccoli. I’m now in a complete panic that because he’s had broccoli over the last few days I’ll have caused him to develop more stones. Do you think the few days will have caused damage ? Is there anything I can do to stop the stones reoccurring? We’re in the UK and have been told they were most likely calcium stones.

thank you