A Horse passport is based on the identification of the animal by a veterinary surgeon. The animal is microchipped and has a silhouette completed with all its markings.
The passport contains Medication pages which includes a declaration stating whether or not the animal is intended to enter the food chain (for passports issued from 2003 to 2015 this is Section IX and from 2016 onwards Section II).
Vets need to see this section of the passport before they treat an animal to determine what medication can be administered. If the animal is not signed out of the food chain it limits the drugs the animal can be given.
The passport system protects food safety and enables the UK to continue using veterinary medicines that are not safe to enter the food chain.
You can be fined up to £5,000 if you don't have a valid passport, registered in your ownership, for each horse, donkey and mule you own.