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The UK has a robust chemical surveillance strategy which covers many areas and APHA and Defra, along with other government agencies, contribute to this programme in a number of ways. The response to incidents can be complex and multifaceted to consider public health, animal health and welfare, feed and food safety, wildlife and environmental safety and sustainability. 


If you suspect a toxicology-related incident, please contact your Veterinary Investigation Officer at your nearest Veterinary Investigation Centre.

APHA’s role in chemical surveillance

APHA’s role in chemical surveillance is through:

  • Screening programmes
    This is targeted surveillance and can be put in place when the hazards are known.  An example of this is the Statutory Surveillance Scheme for Veterinary Drug Residues and to which APHA participates on behalf of the Veterinary Medicines Directorate
  • The Wildlife Incident Investigation Scheme (WIIS), which is run by Natural England and Welsh Government on behalf of HSE, detects incidents that might be associated with the misuse or abuse of agrochemicals in relation to wildlife
  • Emergency response
    Following an incident such as a fire or severe flooding it may be necessary to set up targeted surveillance for predicted known hazards which might be present
  • Animal disease outbreaks
    This forms part of APHA’s scanning surveillance. It is very important as it is how an unexpected or previously unknown hazard might be detected.  The day to day work of a veterinarian in practice and any proactive or reactive disease investigation plays a critical role.  Once a hazard is detected then mitigating measures can be put in place and targeted screening set up to assess outcomes

Food safety

With any poisoning incident which involves food producing animals, it is essential that an assessment of safety in carried out. Under the Food Safety Act 1990 and related legislation, farmers, as primary food producers, and their advisors are required to show due diligence to protect the food chain.

Critical incidents that need immediate action involve those where food products are moved off farm frequently, such and milk and eggs. If an incident is suspected, an immediate standstill of animals and food products should be implemented while facts are clarified and an initial risk assessment is carried out.

How chemical surveillance works best

As with any surveillance, the key activity is making sure that incidents are detected. The linking up of related incidents can serve as a trigger for action and needs to be co-ordinated as chemical incidents are often complex. Therefore, please contact APHA about any suspected incidents, and we can make sure the correct organisations are informed and involved.

Lamb with Vitamin A toxicosisThe image on the right shows a lamb with Vitamin A toxicosis. APHA was initially alerted to three affected farms over two days. As a result of a co-ordinated approach, contaminated milk powder was quickly identified, traced and recalled and the speed at which this could be done helped to minimise the impact.

Disease information reports


APHA publications

APHA chemical food safety reports (livestock)