Multiple title-winning show hunter Grand Slam has been put down.

The six-year-old, ridden by Robert Walker, was H&H’s cover star on 21 May following his success at this year’s Royal Windsor Horse Show.

He had suffered a bout of colic.

Robert told H&H today (Monday 31 August) that the horse had shown “a lot of promise for the future”.

Grand Slam won the novice hunter championship title – a sixth at Windsor for team Walker – and was also one of Robert’s five winners at the show.

“He was a winner and a real tough guy that was as hard as nails right to the end,” Robert added.

“It was awful when I got the phone call from the vet.”

Sarah Walker, Robert’s wife and business partner, shared the news on social media.

“Sad news we have had to have grand slam put down over night with colic, poor boy he was only 6 with a bright future ahead of him, rip Gary xx,” she wrote.

The post received hundreds of comments from people sending their condolences.

“Such a lovely horse taken too soon,” said one Facebook user.

Another said: “I remember the first time I saw him I thought Wow. Yes there was no doubt he was going to have a very bright future.”

The chestnut gelding, by Garrison Royal, also won championship titles this season at the North of England, Great Yorkshire and North West Sport Horse shows.

The Walkers had had Grand Slam, known as “Gary” at home, since he was a foal.

Owned by Jill Day, he was bought from Goresbridge Horse Sales in 2009.

The Walkers are among the top showing producers in the UK and have had countless wins and major shows.