Pressure is mounting on the Agriculture Minister Simon Coveney to deal with the growing problem of abandoned horses around the country.
According to those who own horses, the cost of complying with the regulations often exceeds the value of the animals.
MEP for the North East Mairead McGuinness said: "We do have a problem of surplus horses. Some are being abandoned, either on the side of the road but more likely in very remote parts of the country.
"When an animal is not microchipped, you really cannot identify the owner."
"We are trying to regulate and control what's happening with horses and ponies (but) there seems to be a gap (in the system) where some owners are saying it doesn't pay them to microchip the horses. In fact it costs them a huge amount of money to do so."