Little Josh became the second horse to die at this year’s Grand National meeting after falling in the Topham Chase, which is run over the National fences.

The horse, ridden by Sam Twiston-Davies, suffered a broken shoulder and was later put down by veterinary surgeons.

It followed the death of Battlefront after he was withdrawn during yesterday’s fourth race by jockey Katie Walsh.

Aintree bosses have made significant alterations to the Grand National course after last year’s big race was marred by the death of two horses, According To Pete and Synchronised.

That followed two fatalities in the 2011 race — Ornais and Dooney’s Gate.

Old wooden fence frames have been replaced with “Easyfix plastic birch”, dressed with spruce.

Aintree said the new fences were “kinder if the horse makes a mistake”. The height of the fences remains the same.

Professor Chris Proudman, veterinary adviser to Aintree Racecourse, said: “We are sad to confirm that it has been necessary to humanely put down Little Josh on welfare grounds as a result of a fall at the 15th fence in the John Smith’s Topham Chase.

“He received immediate veterinary attention for a broken shoulder, but this injury was not treatable and it was the necessary course of action.”

The other 28 horses taking part in the race had returned safely.