I am not aware of any recent incidences of illegally imported lambs or sheep. As a member of the European Union, Ireland is obliged to operate within the rules of the Single Market. This means that it is not possible to prohibit the free flow of trade in agricultural produce which is the subject of a common organisation of the market, from other member states.
However, under EU legislation sheep coming from other member states must be accompanied by EU veterinary certification and be assigned to a particular holding/slaughterhouse. A separate certificate applies to each of three categories; i.e., sheep for breeding, sheep for fattening and sheep for slaughter. Details of each consignment of animals imported are required to be sent in advance to the local Department of Agriculture, Food and Rural Development office in the county of destination through the EU Animal Notification System (ANIMO).
Where trade with Northern Ireland is concerned, these requirements have, by bilateral arrangement, been removed since 1992. Under this arrangement, sheep of Northern Ireland origin may move freely into the Republic and vice versa. No animal health certificates are required for such trade and no ANIMO notifications are sent.
Finally, the question of VAT liability on the importation of sheep is a matter for the Office of the Revenue Commissioners.