From the video information: "This horse was bitten by a snake and subsequently developed a large chest abscess. The horse was sedated and given a local block before draining. The horse made a quick and uneventful recovery."
So, the horse was drugged. That's why he just stood there. It was like poppin' a big ole pimple wasn't it?
Abcess help, obtained from a vet:
1) Apply Magnapaste (epsom salt paste) to foot
2) Wrap foot very heavily in cotton bandage wrapping (the kind that comes in sheets - secure it with some 2 inch wide white bandage tape (like athletic tape)
3) Take a large burlap sack and fold it in half (so there are four layers of burlap and place it under the hoof with the toe pointing towards the top (cranial) corner of the burlap
4) Pull the cranial and medial corners of the burlap tight around the pastern/fetlock (which should have some cotton around them) and secure with bandage tape
5) Pull the lateral and caudal corners of the burlap tight over top of the already secured burlap and secure with tape
6) Fold up the two areas of burlap that are still sticking out and then wrap the entire bandage in the bandage tape
7) Soak the foot in warm epsom salt water for 20 minutes. Repeat soaking 1-2 times per day- if you don't soak at least daily, then the burlap will dry out and chafe
9) The second day the bandage is on and then every other day after, add a layer of duct tape to the bandage to keep it from tearing through
10) After the horse has stayed completely sound for two days, stop adding duct tape to the bandage and turn the horse out to walk through the bandage (should be stall rested or confined during treatment)
11) Once the bandage is worn (doesn't take very long, maybe a day or two- remember to keep soaking so the burlap stays wet), cut everything away and tada sound hoof.
This works because the hoof is constantly moistened to allow for the abscess to rupture or dissipate and the epsom salts prevent bacterial growth.
Good luck!