Hi Val, Thanks for that, I've already been in touch through a link on the Brittany site who replied as follows: "We do not have a vet in Santander that is open on Saturday afternoon but we do have a vet who can accommodate you for a Monday sailing. Our fee for arranging this will beThis is from the Brittany Ferries website
http://www.brittany-ferries.co.uk/pet-friendly-holidays/vet-contact-details
If you look towards the bottom of the page, you'll find two vetinerary clinics in Santander - and perhaps if you phone now and explain, they'll make a suitable appointment.