Greyhound Racing Ireland have suspended all racing for the weekend due to soaring temperatures.
Temperatures soared to 30C yesterday and Met Eireann is predicting similar highs over the coming days.
The body said that it was taking the decision in consideration of "the care and welfare needs of racing greyhounds" and will review the situation on Monday when temperatures are expected to fall back to the low 20s.
Meetings at Shelbourne Park, Newbridge, Kilkenny, Mullingar, Galway, Limerick, Tralee, Curraheen Park (Cork), Kilcohan Park Greyhound Stadium (Waterford), Clonmel, Thurles and Dundalk have all been affected.
Racing in Northern Ireland comes under the auspices of the Irish Coursing Club but Belfast's Drumbo Park confirmed to RTÉ that they would also be cancelling their scheduled Saturday meeting.
Greyhound Racing Ireland said in a statement: "Due to Met Éireann's High Temperature warning for Ireland and considering the care and welfare needs of racing greyhounds, Rásaíocht Con Éireann (RCÉ) has announced the previously announced suspension of evening racing and trial activity (after 11am for Friday 12th August) will now be extended until Sunday 14th August (inclusive).
"RCÉ will continue to monitor the position from Monday 15th August and any further notices will be issued regarding the rescheduling of any relevant race meetings on the RCÉ website www.grireland.ie.
"Arrangements are in place at tracks to ensure that additional water points including greyhound baths are available for any activity carried out pre the 11am suspension.
"Owners and trainers are reminded of the importance of good ventilation in transportation arrangements for greyhounds and ensuring that adequate water and other supports are available for all greyhounds. Further advice and information on 'caring for the greyhound in hot weather’ is available on www.grireland.ie"