Vidalta 15mg 100 tablets are used for the treatment of hyperthyroidism and hyperthyroidism-associated clinical signs in cats. A vet prescription is required for the medicine you have chosen. If you do not yet have a prescription then you can print out the following blank veterinary Prescription Form which you can ask your vet to fill in when you next visit. Please note that changes to legislation in 2005 means that Vets must offer you a prescription to take away and not just supply you the medicines directly. This is to ensure more competition and lower prices for you.