Katenko has been scratched from the Betfred Cheltenham Gold Cup and the John Smith's Grand National.
The Venetia Williams-trained seven-year-old had been quietly fancied in some quarters for the Gold Cup after winning his last two races in the manner of a progressive horse.
But he was officially taken out of the Cheltenham Festival highlight on Saturday morning.
Williams has also withdrawn Katenko from the National, for which he was available at around the 20-1 mark.
Williams told the Morning Line on Channel 4 that Katenko underwent an emergency operation for colic on Friday evening which had ruled him for the rest of the season.