The racing industry is in shock after the death of champion racehorse Black Caviar, who captured hearts with her unbeaten 25 consecutive wins.

The legendary thoroughbred mare died peacefully on Saturday, the day before her 18th birthday, after suffering a terrible illness.

Trainer Peter Moody said Black Caviar gave birth to a colt foal in the morning and then she was put down after that on humane grounds, racing website Racing.com reported.

Moody told Racing.com she had suffered laminitis, a painful and crippling hoof condition that can be fatal to horses. He said there was no chance of saving the legendary mare.

“She had a milk infection about a week ago and we just treated it like you do with all broodmares. But, like a lot of treatments, it went straight to her feet,” he said at Caulfield on Saturday.

“Basically, it killed her feet.

“She had the foal this morning, a colt foal by Snitzel, and they put her down shortly after that on humane grounds.

“They scanned her feet yesterday and there was no blood flow at all to her feet. There was minimum blood flow to her feet anyhow but there was none and she’s such a big girl.

“I rang all the staff and told them. They were all very upset.”

Black Caviar had 25 starts over four years from 2009 through to 2013. She won in Melbourne, Sydney, Brisbane, Adelaide and, famously, in front of Queen Elizabeth at Royal Ascot in 2012.

The winner of 15 Group One races, Black Caviar was retired in 2013 after amassing nearly $8 million in prize money.

Moody, who trained the mare to her unbeaten record of 25 wins, reflected on his time with the champion sprinter.

“She was a remarkable horse who gave us all the ride of a lifetime and wonderful memories,” he said.

“I rang all the family and the staff, Paddy Bell and those close with her, and I sat in the car and cried for an hour as I was ringing them.

“You don’t think it affects you, but it does. It’s impossible not to get attached to most animals, but one like her, you cannot but do so.

“You get reminded of her almost every day whenever you turn on the TV, there she was shooting past the post.”

Victoria Racing Club chairman Neil Wilson extended his condolences on behalf of the club.

“Today’s news is a shock to us all. Black Caviar was more than a champion racehorse, she was an important part of life for many people,” said Wilson.

“Her brilliance, her presence and the pleasure and inspiration she gave to so many was a special moment in time for horse racing and sport more generally.

“She has created a piece of history that will be remembered forever, and it was a privilege for all who saw this wonderful equine athlete in action.”

-with AAP