Passports were introduced to ensure that veterinary medicines currently available within the UK were not withdrawn from market.
Approximately 75% of medicines, including Bute, have not been tested to see how long they take to withdraw from the animal's body. This means for the few equines that are slaughtered for human consumption they presented a risk to human health if they had been treated with these medicines.
By identifying your horse via a "horse passport" and signing an irreversible declaration (Section IX) in the passport stating that it is not intended for human consumption your horse has access to the widest range of veterinary medicines. The legislation within England, Wales Scotland and Northern Ireland about when you need to sign this section varies so please read it carefully.
Information regarding horses in UK is stored in the National Equine Database (NED) for use by DEFRA and members of the public are expected to have access to reports from NED by Summer 2007.
An added benefit of the passport legislation is that it is offering protection to horse buyers. They are now able to check the details of the horse against its passport before they buy it and even contact previous owners. Trading Standards officers are also using the legislation to prosecute horse dealers who are flouting the law.