A third horse died at this week's Aintree Festival following a fall in a race run over the fences used for the gruelling Grand National Steeplechase.
Gullinbursti died because of injuries sustained in a fall in the Topham Chase on Friday, the British Horseracing Authority said.
Another horse, Minella Reception, was being assessed after a fall in the same race.
On Thursday, Clonbanan Lad and Marasonnien died after being pulled up by their jockeys in the Fox Hunters' Chase - also run on the Grand National course - and later collapsing.
Neither of those horses was injured by a fall, the BHA said.
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Earlier, the biggest favourite of the festival proved a big disappointment.
Vautour - a 1-5 shot ridden by leading jockey Ruby Walsh - fell while leading the Melling Chase, allowing God's Own to take a surprise win in the day's feature race.
Vautour landed steeply after jumping the ninth fence and fell in the biggest shock of the festival so far. God's Own benefitted by beating Al Ferof to the winning post at odds of 10-1.
It was a major blow for Irish trainer Willie Mullins, who is vying with Paul Nicholls to be the champion trainer in British racing with two weeks left in the jumps season.
The Grand National, the world's toughest steeplechase, is run on Saturday.
