The European background
By now those of you who either possess and / or have day to day charge of any horse should have applied for a passport (horses mean all members of the equine or asinine species or crossbreeds of those species, but it does not include zebras!). Passports are obtained from “passport-issuing organisations” including breed organisations that maintain stud books.
In 1990 the European Council issued a directive on the “zootechnical and genealogical conditions governing the intra-Community trade in equidae”. This acknowledged that horses, as live animals, fell within the Common Agricultural Policy and that the breeding and trade in horses, within the European context, is regarded as part of the farming sector and, as a source of income, should be encouraged. The directive also acknowledged that the disparate way in which entries in stud books (which governed the breeding of horses) were maintained, presented a barrier to trade.
Therefore a framework was established in what needed to go into stud books and how they were managed. In particular it required a mechanism whereby the Member States would approve those organisations that issued passports. In the subsequent Commission Decisions there are even more overt references to freedom of trade and the need to non-discriminate between breeders within the Community.
The maintenance of stud books initially impacted on the trade in recognised breeds of horses where the value of the horse was in its breeding as opposed to its value as meat. But on the continent there is a traditional and significant trade in horsemeat for human consumption that needed to fall into the developing framework for identification and tracking of animals. This was to ensure that humans did not end up eating horsemeat that came from horses that had been treated with drugs inappropriate for human consumption.
As the trade in horses will be governed under the Common Agricultural Policy the logical conclusion is that all equidae are required to have passports.
Thus the way that stud books are run and passports administered, relate to freedom of trade and the need to have a uniform and accountable system of monitoring animal health and movement.