1.—(1) A veterinary surgeon acting under this paragraph may either administer a veterinary medicinal product prescribed by him personally or may direct another person to do so under his responsibility.
(2) If there is no authorised veterinary medicinal product in the United Kingdom for a condition the veterinary surgeon responsible for the animal may, in particular to avoid unacceptable suffering, treat the animal concerned with the following (“the cascade”), cascaded in the following order—
(a)a veterinary medicinal product authorised in the United Kingdom for use with another animal species, or for another condition in the same species; or
(b)if and only if there is no such product that is suitable, either—
(i)a human medicinal product authorised in the United Kingdom; or
(ii)a veterinary medicinal product not authorised in the United Kingdom but authorised in another member State for use with any animal species (in the case of a food-producing animal, it must be a food-producing species); or
(c)if and only if there is no such product that is suitable, a veterinary medicinal product prepared extemporaneously by a pharmacist, a veterinary surgeon or a person holding a manufacturing authorisation authorising the manufacture of that type of product.
(3) In the case of a veterinary medicinal product imported from another member State, if the veterinary surgeon has not obtained a certificate from the Secretary of State under regulation 25(5) permitting him to import it, he must obtain a certificate from the Secretary of State before he administers it.
(4) Any pharmacologically active substances included in a medicinal product administered to a food-producing animal under the cascade must be listed in Annex I, II or III to Council Regulation (EEC) No. 2377/90.