Theoretically, if you taking/sending a horse or pony abroad, the animal needs vet's papers via defra, cost almost 60 quid, and horse must be over 14.2hh or have a special valuation certificate, or being registered with breed association, before it will be allowed out from the country. And of course, passport signed "not for human consumption". How they're getting over these rules I have no idea.
they are and they have been for years-many of them go through Ireland, or used to. The importing of inadequately health checked horses is also a grave concern.