I found a baby mockingbird & I think he may have bumblefoot?

It on his left foot && on the top. It's at the joint and it just like swollen and pink. He keeps lifting it up. & I think on the back of his foot there might be a cut, between his back toe and his leg. What can I do? As he's a wild mockingbird & a vet won't treat him. && Can birds get bumblefoot on top? Cause all the pictures I've seen have been bottom of their feet?