A horse welfare charity has welcomed the four-year ban given to trainer Howard Johnson.
Johnson, who said he now planned to retire, admitted running Striking Article eight times after the horse had a palmar neurectomy.
The operation involves severing or removal of leg nerves running to the foot and leaves the horse numb to pain.
"This was a reprehensible act," said Roly Owers, chief executive of the World Horse Welfare charity.
"It clearly crossed the line between the acceptable and unacceptable use of horses in sport.
"When we use horses in sport, that places a significant burden of responsibility on our shoulders for their welfare, and Howard Johnson simply did not live up to that responsibility.
"He showed a callous disregard for the well-being of the horse when he made the decision - not once but eight times - to run Striking Article without any feeling in one of his forefeet."
Johnson, 58, claimed during a British Horseracing Authority (BHA) inquiry he was unaware of the rule stating he should not have run the horse.
The BHA disqualified the National Hunt trainer for three years with regard to the neurectomy charges, and one year for using anabolic steroids on three other horses.
Johnson indicated when contacted that he had no plans to appeal against the suspension and that he intended to retire from training. He plans to issue a full statement early next week.
Johnson's principal racehorse owner, Sage computer magnate Graham Wylie, said he was "absolutely, totally shocked" by the ban.
"Howard has been treated like a criminal and he is not," he said.
"I think it's a disgusting decision and I'm disappointed for Howard.
"I just feel so sorry for him because that is not Howard and he looks after his horses incredibly well. He would never do anything to harm a horse.
"I think they (BHA) have come down too heavy handed for the charges that have been made against him.
"It is a very sad day for northern racing as it has lost a very good trainer and they have also lost a very good owner.
"Most of my horses will go the sales and the rest of those that I keep will either go down south to be trained or to Ireland. I shall spend the weekend thinking about it.
"It's a very sad day."
Johnson said the horse would not have pulled up on his final start [at Musselburgh in February 2010] if he had no feeling in his foot.
Striking Article was put down after that race. It was discovered in the post-mortem that the neurectomy had taken place.
Johnson said he was not aware of the rules and did not know that a horse that had been de-nerved was banned from racing on welfare grounds, and because it could affect the safety of the jockey.
But Owers said: "We are also dismayed that a trainer of Johnson's experience and stature is pleading ignorance of the rules. Ignorance is no excuse for not knowing the rules but more importantly it's no excuse for cruelty.
"Looked at another way we just need to apply a little simple common sense: how could anyone think it was acceptable to race a horse that was in so much pain it needed a neurectomy in the first place?
"This case should send out a clear message to everyone involved in racing that the welfare of the horse has to come first, not the need to win at any cost."