Its totally and utterly pointless doing 'extra' A levels.
No Uni requires more than 3 subjects, and any others will just be ignored.
They do not think 'oooo clever' or give you any extra brownie points.
For Vet, you need Chem, Bio and one other subject at AAA or above.
You can study Spanish as an extra-curricula subject at most Unis.
Remember, AAA will always look better than ABBB - and that could cost you a Uni place.