Time and again disputes occur as to who the rightful breeder of a horse is. Often these disputes do not arise at the time the foal is registered with a studbook, but when said foal has grown into an athlete that competes and performs successfully at top level.
Arguments can be made that the person responsible for the creative pairing of pedigrees should be considered the breeder, or that the person who registers the foal with a studbook is its breeder. But there are many grey areas, for instance embryos that are purchased & carried to term in surrogate mares. Is the breeder the person that was responsible for the conception of the embryo? Or the owner of the mare at the time the foal was registered, even if the mare in this case is not even the biological dam of the foal?
Due to disputes that have occurred in relation to this issue not only between breeders but also between studbooks, the WBFSH has often been called upon to make a statement as to who the rightful breeder of a horse is. At the last two joint meetings of the WBFSH board and executive committee this issue was debated in depth. Following these deliberations, the WBFSH recommends that:

“Unless there was a contractual agreement at the time of sale of a pregnant mare, whereby the rightful breeder of the foal in utero sold with the mare is clearly defined, the rightful breeder of a foal is the entity that owned and/or had full rights to the mare (in the case where a mare may be leased for a breeding season) and registered the foal upon its birth with a studbook to obtain registration papers.”