There is no direct importation of horsemeat into the EU from the USA. The slaughter of horses for human consumption within the US ceased in 2006. I understand however that significant numbers of live horses are exported from the US for slaughter in both Canada and Mexico. Some of this meat is then exported to the EU. I am not aware that any of this meat has ended up in Ireland, where the level of consumption of horsemeat is very low.
The Regulations relating to the import of meat from third countries are set at EU rather than at domestic level. The basic requirements for imports of meat are set out in Regulation (EC) No 853/2004. The third country of dispatch must be on an approved list for that product and the individual establishment from which the product is dispatched must also be on an approved list. These lists are published on the EU Commission’s website. There is also a requirement that imports of meat are only allowed from countries with an approved residue monitoring plan.
The EU Food and Veterinary Office (FVO) conducted audits in Canada (in 2011) and Mexico (in 2012). These audits raised some concerns about the identification of US horses being slaughtered in both countries and the question of compliance with standards equivalent to those provided for by EU legislation in relation to non-treatment with certain medicinal substances.
The EU Commission is I understand in close contact with the countries involved to have the FVO audit recommendations followed up satisfactorily.