The coffin bone is the last bone in the skeletal leg. The laminae tears away from the hoof wall, allowing the horse's weight to move the coffin bone within the hoof. The bone may be pushed down into the sole of the foot, resulting in painful lameness. It is difficult for horses to take weight off their feet because they don't like to lie down. Fluids are trapped in the front of the foot similar to a blood blister under the fingernail.
Secondary problems can develop.
Horses with acute laminitis are lame, depressed, off feed and reluctant to move. All feet are susceptible, but most often the weight-bearing front feet are affected. He said the condition needs immediate attention from a vet and farrier. Otherwise, it risks becoming a chronic condition or results in deformed hoof bones. The vet must go to the horse, because loading the horse into a trailer could worsen the condition.