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Off label medication use

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Podcast: Off label medication use

Legal requirements


  • In the United States veterinarians may use or prescribe non-food animals any medication approved by the Food and Drug Administration (FDA) for use in either animals or humans.
  • Very few restrictions apply for this off or extra label drug use in companion animals, eg veterinarians are not required to preferentially use products approved for use in veterinary species and they may choose a particular medication based on cost issues alone.
  • In contrast, in the United States, there are numerous restrictions on off or extra label drug use in animals intended for human consumption, eg veterinarians can only resort to off label use if there is no effective agent approved for use in that species. In addition, it is the veterinarians responsibility to ensure that tissue residues do not result from off label drug use.


  • In the United Kingdom a veterinarian may prescribe any veterinary medicine out with the datasheet recommendations, or any preparation licensed for use in humans provided there is no appropriate veterinary licensed alternative.
  • The prescribing "Cascade" must be adhered to in these circumstances, for further information see AMELIA8 (British Veterinary Association (BVA) Code of Practice on Medicines).
  • It is essential that the veterinarian informs the client if they intend to prescribe a medicine for the client's animal, which is unauthorized for use in that species or for that particular purpose.
  • Such situations also apply to a specially prepared unauthorized medicine ("special-order product") or a medicine imported from another country under a Special Treatment Authorisation (STA).
  • Clients must be warned of the potential side effects and risks associated with the use of the drug before prescription. 
  • All clients in this situation should be asked to sign a form giving their consent to the use of the product in their animal AFTER all the implications of medicine use have been explained to them.
  • Examples of suitable Consent Forms for "Off label" use are obtainable from the Veterinary Defence Society Ltd (VDS):
    • If medicine is to be used long-term, eg anticonvulsant, use lifetime consent form.
    • For use only once, use single consent form.

The person who signs the consent form should be over 18 years of age.

As a claim can be instigated up to 6 years after an event, the VDS advise that all consent forms should be kept for 6 years in case legal dispute arises.

Information to be inlcuded on consent forms

  • The consent form should contain:
    • Name and address of veterinary practice prescribing the treatment.
    • Name and address of client whose animal is to be treated.
    • Full details of animal(s) to be treated (name, breed, identification, sex, etc).
    • Relevant clinical history.
    • A statement to the effect that the owner is aware of any potential side effects of the treatment and that they understand the medication has no license for use in their animal.
    • A declaration that the owner has read and understood the form.
  • The form should be signed by the owner who must add the date of signing and print their name beneath the signature.

Further Reading


Refereed papers

Other sources of information

  • Animal Medicinal Drug Use Clarification Act (AMDUCA).
  • British Veterinary Association (BVA) - Code of Practice on Medicines.
  • British Small Animal Veterinary Association (BSAVA) - Small Animal Formulary.
  • The Medicines (Restrictions on the administration of veterinary medicinal products) Regulations 1994 (SI 1994/2987) Guidance to the Veterinary Profession. AMELIA8, March 1995.
  • The Veterinary Formulary. 5th edn. Pharmaceutical Press in association with BVA.


  • American Veterinary Medical Association (AVMA), 1931 N, Meacham Road, Suite 100, Schaumburg, IL 60173-4360, USA. Website:
  • British Small Animal Veterinary Association (BSAVA), Woodrow House, 1 Telford Way, Waterwells Business Park, Quedgeley, Gloucester GL2 4AB, UK. Tel: +44 (0)1452 726700; Fax: +44 (0)1452 726701; Email:; Website:
  • British Veterinary Association (BVA), 7 Mansfield Street, London W1G 9NQ, UK. Tel: +44 (0)20 7636 6541; Fax: +44 (0)20 7436 2970; Email:; Website:
  • Food and Drug Administration (FDA), 5600 Fishers Lane, Rockville, MD 20857-0001, USA.
  • National Office of Animal Health (NOAH), 3 Crossfield Chambers, Gladneck Way, Enfield, Middlesex EN2 7HE, UK. Tel: +44 (0)181 3673131; Fax: +44 (0)181 3631155.
  • Royal College of Veterinary Surgeons (RCVS), Belgravia House, 62-64 Horseferry Road, London SW1P 2AF, UK. Tel: +44 (0)20 7222 2001; Fax: +44 (0)20 7222 2004; Email:; Website:
  • Royal Pharmaceutical Society of Great Britain, 1 Lambeth High Street, London SE1 7JN, UK. Tel: +44 (0)20 7735 9141; Fax: +44 (0)20 7735 7629; E-mail:; Website:
  • Veterinary Defence Society Ltd (VDS), 4 Haig Court, Park Gate Industrial Estate, Knutsford, Cheshire WA16 8XZ, UK. Tel: +44 (0)1565 652737; Fax: +44 (0)1565 751079. The VDS offers guidance on consent forms for use in practice.
  • Veterinary Medicines Directorate (VMD), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK. Tel: +44 (0)1932 336911; Fax: +44 (0)1932 336618; Email:; Website: