You don't need any convincing. Doing whatever pops into your mind feels right. Fun. You notice the boy rise to two feet, apparently giving up, he leaves. "Jaawwny, looks like weeeeehaw have it to ourselves!" You do what the boy had done. When you drop to you hands and knees with your back to the fence, you can almost feel your mind emptying. Being on all fours like an animal made you feel very dumb, but happy! Johnny was on the ground next to you.
"Let's do it!" He says
You look back then kick back with both feet repeatedly. As you do, you can feel a pressure rising in your chest, realizing what it is, you happily let it out. "HAWWWW HEEE HAW HEEEE HAWWW!' You bray as you kick harder and harder. You and Johnny don't even notice when your shoes fly off. With a final bray you kick one last time, and feel your feet connect with the fence in a way you hadn't before, as if your feet were hard. You hear the fence fall. Looking back, you see shiny black hooves at the end of your legs, feeling them with a hand, they feel so hard. Instead of panicking, this makes you happy. "Joaaawwwwny! Looks like we won't need shoes again!" You say, noticing the hooves on the end of his feet. Getting shakily to two legs, you head through the busted fence.