You struggle with the doorknob as you feel the hooves on the ends of your arms seem to be getting a tighter feeling, becoming number and immobile. You decide to attempt to use both of your elbows to attempt to pull open the door. But as you struggle with this decision, your arms begin to lengthen, straightening out in front of you, becoming less flexible.
Suddenly, an intense pain emanates along your spine.You feel cracking and pulling all along your spine, and you find it more and more difficult to breath. You end up falling to the ground. You fall on your right side. For a moment, the pain eases and you can breath normally again. You look down and take stock of what just happened. White hairs are growing up your chest, but more importantly, your arms are now LEGS, and your legs are now HIND LEGS. Four legs with hooves on the ends. All four legs are spread outward, and you cannot manage to stand up. You quickly realize you are now permanently quadruped, never to walk on two legs ever again.
Suddenly, breathing becomes labored again as you feel a tightening of your chest. You feel it expanding, as your rib cage seems to explode outward. After a few minutes, that pain ceases once again, but your breathing is still labored. Looking down, you are now completely covered in white hair, and looking over your side, it's all grey. Your body is now nearly complete.