First of all does he have foot rot? Is the skin between his toes look inflamed/cracked/irritated? I would make sure you clean inbetween his toes really well with a hose and brush. If it looks like he has any foot rot just spray some copertox in there.
If that is not the case- have you had a hoof trimmer take a look at him? I had a cow one time that the vet said twisted her ankle a little. I had the hoof trimmer come out and take a look and he found a 6in nail that went straight up between her toes. I have no idea how she didnt' get an infection in the bone and die.
I don't really know of much you can do for his feet if he just has tender feet. You can't give him any pain relievers (at least here you can't) Hopefully someone will have more advice for you!
I would have a vet check him. If it is foot rot, he can be treated, but with withdrawl time on the drugs, it needs to be done ASAP. If he is abcessed from acidosis, you need his feet trimmed right away so it has time to heal. Good Luck!
This won't help you much now, but it's something to keep in mind. Adding zinc ( zinpro) to the feed seems to help us with hoof health. Also, check with your vet about vaccinating for foot rot. I believe the product is Fusiguard. Good luck.