The dramatic scratching of imported stallion Changingoftheguard yesterday morning forced McKenna to relive his 2007 experience with another David Hayes-trained stayer The Fuzz, which was also ruled out hours before the big race.

The Warrnambool businessman, a part-owner of Changingoftheguard and The Fuzz, said he couldn't believe the outcome of the early morning inspection by three Racing Victoria veterinarians.

Racing Victoria's chief vet Dr Paul O'Callaghan and his colleagues diagnosed lameness in the European import's off foreleg.

"I'm totally gutted," McKenna said. "It would be the most disappointing time I've had in racing.

"The first hint that I had that something could be wrong was around five o'clock yesterday when David rang. But David assured us that the horse was not sore.

"We've had continual phone calls this morning and he (Hayes) phoned me just after 7.30 this morning to say that the vets wouldn't let the horse run."

McKenna said The Fuzz, who had a foot abscess, was scratched from the 2007 Melbourne Cup by Hayes when he pulled up sore after light track work. Hayes was furious with yesterday's scratching, criticising the veterinary assessment and labelling the vets "knuckleheads".

"They see lameness that is not there," Hayes told reporters at Flemington.

"The horse is not lame.

"I had the horse trot in front of the TV cameras to show everyone that he was sound. I've never been so insulted in my life," Hayes said.

Hayes said he would not have paid the $45,000 final acceptance fee if Changingoftheguard was lame. The horse's cup lead-up was interrupted by a foot abscess two weeks ago but he recovered and worked well on Sunday.

Hayes sympathised with his high-profile owner.

"It's very, very disappointing for Colin," he said.

"I feel sorry that the horse couldn't take its place in the field. We scratched The Fuzz on the Tuesday morning because he was sore but this horse was not sore in my opinion. Let's just hope that Colin's bad luck does not happen for a third time."

McKenna said the owners would try to put the episode behind them and look to the future. McKenna did have some good fortune at Flemington when another horse he part-owns - Flying Tessie trained at Wangoom by Matthew Williams - won the last race, a 1400-metre handicap.

''I think David will spell the horse now until the autumn, bring him back for next year and have a shot at next year's cup," he said.

McKenna was still on course to watch another runner he has an interest in.