Thank you for your advice and concern. I had already told him to increase hay and reduce the concentrate to 2 kg and feed a protein balancer because the riding school will not allow free choice hay.
Why do you believe he would be tying up? Is the Holsteiner breed prone to it?
He is 620 kg right now. Is quite a big horse and very well muscled
Also Lavinia, I just remembered now, do you suggest any way to avoid flies and infection in the crack?