Gold Dancer had to be put down after suffering a broken back when winning the Mildmay Novices’ Chase on day two of the Grand National Meeting at Aintree.

The horse dragged his back legs through the final fence when leading Regent’s Stroll and was ridden out to win by four lengths under Paul Townend for trainer Willie Mullins.

Gold Dancer was immediately pulled up after crossing the finish line, with Townend dismounting and screens erected for veterinary experts to assess and treat the horse but the seven-year-old was put down.

Owners Gigginstown said: “He’s been put down. He broke his back. It’s terribly sad for the horse.

“What could Paul Townend do? He felt fine, it was just when he pulled up that something was wrong.”

Emma Slawinski, chief executive at the League Against Cruel Sports, said: “Year after year we see horses dying at Aintree for people’s entertainment and a cheap bet. Sadly, Gold Dancer is the latest victim of this heartless spectacle, which flies in the face of animal welfare.

“The public and businesses should boycott the Aintree Festival, refuse to bet on the racing, and stop watching the ITV coverage and advertising which glosses over the animal cruelty.

“The government needs to act as the British Horseracing Authority and Jockey Club is prioritising gambling profits over the lives of the horses.”

James Given, director of equine health and welfare for the British Horseracing Authority, said: “The horse jumped and slipped and lost his back end.

“He came up very quickly and took one half stride to get organised and galloped away.

“I was in the inquiry and gave evidence that looked into the incident – I was able to watch front on and behind – and the horse stayed as straight as an arrow and wasn’t deviating off a straight line or being asymmetric, the back legs were following the front legs exactly.

“It was only when they went past the finishing line that he turned around to the left as the track goes and went from cantering to a trot and the action changed and Paul [Townend] became aware.

“He immediately jumped off and was attended by the vets. I don’t believe Paul was able to notice that injury at all.

“He would have felt nothing but normal to him and it was only from the action from a canter to a trot he became aware and acted exactly as he should have done.”

Two horses, Willy De Houelle and Celebre D’Allen, died at last year’s Aintree Festival.