Did the vet perform an ultra sound of the tendon to determine the degree of injury? I agree, the tendon will never be as a strong as it once was. Yes! There are things you can do to prevent further injury. I cold hose and poultice. I have heard differing opinions on support boots. For instance, some experts say they constrict the movement of the tendons and ligaments. Sometimes those rear boots don’t fit well and tend to stretch out and slide down presenting a safety issue for horse and rider. If you have boots that fit well I would discuss it with your vet to make sure they are right for your guy. Either way, support boots will not guarantee no further injury. My best advice is be on the lookout for heat or swelling. After a competition, poultice and give him a couple days off. A little R&R will help him recover.