Have let vet use immobilizer on one animal. NEVER AGAIN. As far as I can tell the animal still feels the pain 100%, it just can't move because its voluntary muscles are paralyzed. I thought it was incredibly inhumane, like happens when people wake up during surgery and can feel the pain but can't move. The website for the "main" brand of immobilizer says it immobilizes the voluntary muscles only, I believe. Yes certainly it makes it easy for the handler, but the animal still feels the pain. At least that's how it seemed to me and that jives with what I read about how it works, only effects the voluntary muscles, the pain is still there. I could be wrong but the way the animal breathed and how the eyes looked, it was in terrible pain.
BTW for dehorning I have my vet use lidocaine and also give a shot of Banamine, which I repeat in 24 hours sometimes. Very little pain involved, the nose tong is on only for a minute or two. Do this when the horns are maybe an inch long or a bit shorter, before they are very well attached to the skull, won't leave a hole, at least in some breeds. I read that having a nose tong used for a prolonged period can make the animal never forget and be chute shy, it's best to use the tong for as brief a time as possible--my vet puts it on, administers the lidocaine, takes the tong off, and after ten minutes or so when the lidocaine is in effect, puts it back on for the dehorning and cauterizing.
