FOI release

FOI2026/00567 - Substance use on salmon farms

Published 10 June 2026

1. Your request

I am requesting information relating to the prescription and use of veterinary medicines in UK salmon aquaculture, with a particular focus on medicines used under the cascade.

For the period 1 January 2020 to present, please provide:
1. Any data held by the Veterinary Medicines Directorate on the prescription, supply, or use of veterinary medicines in salmon farming, including both:
     *    Medicines with Marketing Authorisation (MA), and
     *    Medicines used under the cascade
    
2.  For the following substances, please provide (where held):
 
     *   The number of prescriptions issued per year
     *   The total quantity supplied or prescribed (e.g. kg) per   year
     *   Whether the substance was used under cascade provisions

Amoxycillin trihydrate
Chloramphenicol
Ciprofloxacin
Difloxacin
Enrofloxacin
Erythromycin
Flumequine
Furaltadone
Furazolidone
Nalidixic acid
Neomycin
Nitrofurantoin
Nitrofurazone
Oxolinic acid
Oxytetracycline Hydrochloride
Sarafloxacin
Trimethoprim
Ivermectin
Praziquantel
Diflubenzuron
Teflubenzuron
Panacur

3.     Any compliance, inspection, or enforcement data relating to the use of non-authorised or cascade medicines in salmon farming.
If the VMD does not centrally hold detailed prescription data, please confirm:
  *   Whether such data exists but is held by veterinary practices or other bodies
 
  *   Whether the VMD has access to or audits these records
 
  *   What data is collected or reviewed as part of regulatory oversight

2. Our reply

We do not collect or maintain data on the prescription or use of veterinary medicines in salmon farming, including products supplied for use under the Cascade. Therefore, we do not hold the information you have requested.

The VMD is responsible for regulating the safe, effective and responsible use of veterinary medicines in the UK. As part of this role, the VMD inspects veterinary practice premises (VPPs) to ensure that veterinary medicines are stored, supplied, and managed in compliance with the Veterinary Medicines Regulations (VMR).

The full VMD Inspection Criteria for VPPs are published on GOV.UK and set out both legal requirements and good practice expectations: https://www.gov.uk/guidance/inspection-criteria-for-veterinary-practice-premises.

We do not have any record of compliance, inspection, or enforcement activity relating to the use of non-authorised or cascade medicines in salmon farming.

While they do not hold a central database of every prescription, the Royal College of Veterinary Surgeons (RCVS) manage the Practice Standards Scheme (PSS), which ensures practices maintain proper records, and they regulate the professional conduct of vets.

Our Product Information Database contains information about veterinary medicines authorised in Great Britain and Northern Ireland. There is only 1 product authorised for use in Salmon that contains an active substance from your list, Oxytetracycline Hydrochloride.

It is the VMD’s established approach not to disclose sales data for active substances where the market is so narrow that aggregation does not meaningfully protect commercial confidentiality. Therefore, we are refusing this part of your request under Section 43(2) (commercial interests) of the Freedom of Information Act 2000.

2.1 Public Interest Test

Factors in favour of disclosure

• Transparency and accountability: Disclosure would support openness regarding veterinary medicines used in aquaculture, enabling public scrutiny of how veterinary products are supplied and used in the UK. This aligns with the principles of the FOIA and the wider government transparency agenda.
• Public understanding of regulatory activity: Releasing the information may help the public understand how veterinary medicines are monitored and authorised, particularly in sectors where environmental and animal health concerns are frequently raised.

Factors against disclosure

• Prejudice to commercial interests: The market for veterinary medicines in salmon aquaculture is extremely small. Disclosure of sales data for individual active substances in such a narrow market would allow competitors and other third parties to infer commercially sensitive information about specific companies, including market share and business strategy. This would be likely to harm the legitimate commercial interests of those companies. This reflects the VMD’s established approach where narrow market data cannot be aggregated sufficiently to protect confidentiality.

• Undermining supplier–regulator confidence: Disclosure of commercially sensitive data may undermine the confidence of pharmaceutical suppliers in sharing information with the VMD on a voluntary basis. This could negatively affect the VMD’s ability to maintain effective regulatory oversight.

• Impact on competition: Revealing commercially sensitive market information could distort fair competition in a small industry sector, which is contrary to the public interest in maintaining a level and competitive marketplace.

On balance, the public interest in maintaining the exemption outweighs the public interest in disclosure. While transparency and accountability are important, disclosure in this case would be likely to prejudice the commercial interests of companies operating within a narrow market, and this would not serve the broader public interest. We therefore uphold the application of Section 43(2) of the FOIA to withhold this information.