Around 4,000 horses have been slaughtered in British and Irish abattoirs since 2019, according to a BBC Panorama documentary.
Successful racehorses linked to Irish racing were among those killed.
Horse Racing Ireland says it unreservedly condemns the practices shown in images from one of the UK’s biggest abattoirs.
H-R-I say it supports calls for an investigation by the relevant authorities.
Speaking to South East Radio News, Leo Powell of the Irish field says race horse owners have a duty of care to their animals and should bring about end of life with dignity and respect, if there is no alternative.