Two high-profile equine deaths at the Cheltenham Festival on Friday heaped more pressure on the sport to improve its image.
The death of Sir Erec after he broke a leg in the first race cast a shadow over the day.
Then in the Magners Gold Cup the Willie Mullins-trained Invitation Only had to be put down after a fall.
Last year, six horses died at the Festival and a seventh was put down following complications linked to an injury sustained at the meeting.
A number of changes had been introduced, including compulsory pre-race vet checks and reduced runners in some races, and on Wednesday there was just one faller from 112 runners.
Nick Rust, chief executive of the British Horseracing Authority (BHA), said that British racing had been 'showcased at its very best' this week but that the three fatalities would be reviewed.
The incident involving hot favourite Sir Erec took place halfway through the Triumph Hurdle - which was televised on ITV - and was particularly tragic because the four-year-old broke a leg on the flat and instantly broke down.
The colt had recovered from a stone bruise last week and had to be re-shod just before the race after losing a shoe, but was considered fit to race and started the race strongly.
Following his death the BHA confirmed that it was 'one of those catastrophic injuries that will occur unexpectedly and we are not able to predict'.
The death of Invitation Only added to the death of his stablemate Ballyward on the final race of day one, the National Hunt Chase for amateur jockeys, which stood out in the week for its high number of incidents.
Following Sir Erec's death, David Sykes, director of equine health and welfare at the BHA, said the horse had passed all pre-race veterinary checks.
Asked if his fatal injury could have been linked to being re-shod, he said: 'Putting a shoe on a horse at the start is not going to cause that sort of injury.' A report from the stewards also noted that full radiograph images of Sir Erec were taken in the days leading up to the race, and there was no evidence to suggest he would suffer an injury.
On the three fatalities, Rust said: 'Our thoughts are with everyone connected to the horses. While the overall injury rate has reduced significantly this year, there will always be an element of risk that can never be entirely eliminated.' RSPCA equine consultant David Muir said: 'I am gutted that any horses have died. I will go through every single death and look to see if there was anything there that was avoidable.'