Authorisation territories

The prescribing cascade

Where there is no suitable veterinary medicine authorised in your territory for the specific condition in the animal being treated, to avoid unacceptable suffering, you can use your clinical judgement to treat animals under your care in accordance with the prescribing cascade.

This is a risk-based decision tree which applies differently in GB and NI. Use the one for your territory to make prescribing decisions on a case-by-case basis.

The Cascade is set out in sequential order of suitability and you should consider the steps in order. It is your responsibility to determine the product that is most suitable for use in the individual animals, which may be based on product characteristics (such as pharmaceutical form or strength), prior evidence or experience of use and/or availability of medicines.

There are special considerations for food-producing animals detailed in our guidance. 

Importing a medicine

Should you need to use a product not authorised in your territory, such as importing veterinary medicines authorised in GB to NI or from outside the UK, you will need to apply for a Special Import Certificate.  You must check with suppliers that it is available before you apply, and you must have your certificate before you buy.

Importing controlled drugs

Products which fall within the scope of the Misuse of Drugs Regulations 2001 may need an additional approval from the Home Office.

Vm numbers tell you where a product is authorised

• if the Vm number begins with XXXXX/5XXX then it is authorised for veterinary use in Great Britain
• if it begins with XXXXX/3XXX or EU/X/XX/XXX/XXX then it is authorised for use in Northern Ireland
• if it begins with XXXXX/4XXX then its authorised in both GB and NI 

If a product doesn't have a Vm number then its not authorised in the UK

They may be authorised in another country, be authorised for human use (PL number), or specially compounded/manufactured for a specific animal and use. These products are unauthorised, and only a veterinary surgeon can prescribe these under the Cascade on a case-by-case basis after a clinical assessment of the animal under their care.

Products prescribed under the cascade cannot be advertised or promoted

This is because they do not hold a veterinary marketing authorisation in the UK, and therefore have not been subject to a full assessment of quality, safety and efficacy. Veterinary surgeons should only proceed with treatment when satisfied that a positive benefit:risk assessment has been reached for the animal(s) under their care.