05/10/2026
Bulging sole where the coffin bone has sunk.
In this section you can see the tip of the coffin bone (P3), I’ve outlined it , and it is sitting far lower than it should within the capsule. That space beneath it should be occupied by healthy, well-produced sole. It isn’t.
The connection to the inner hoof wall has failed, and once that happens the horse’s weight and gravity don’t just load the foot, they drive the bone downward.
Look at the apex. That sharp margin of bone is now sitting directly above the sole plane. Over time, that pressure compromises the circumflex blood supply — the very supply that feeds the cells responsible for producing sole.
Those cells stop functioning properly.
So instead of a firm, protective sole, you’re left with tissue that feels soft, almost spongy under thumb pressure. Not because it’s “good sole” — but because it’s not being produced or maintained as it should be.
You can often start to see the shape of the bone through the sole. The foot is literally telling you what is happening internally.
This is frequently mistaken for a subsolar abscess by inexperienced folk.
It isn’t.
This is mechanical and vascular failure combined.
We talk a lot about rotation in laminitis, but sinking like this is a very different and far more serious level of pathology.
Once the laminar connection fails - enough not to hold the weight of the horse anymore, the bone will plunge down.
Some say the capsule moves up… whatever you want to call it and debate it, it looks like sinking to me and it’s devastating.
Note at the coronary groove where the wall is created, there is a black line that’s pointing down. That’s the soft newly formed wall tissue that been dragged down with the coffin bone.
Zoom in at that area, the sockets in the coronary groove have been pulled down. The coronary groove which should be a distinct “c” shape has been pulled down and is looking straighter.
In the live horse, there will be a distinct dip between top of wall and hair.
