The licence holder shall ensure that where the holder applies a regulated procedure death as the end-point of the procedure is avoided as far as possible and is replaced by an early and humane endpoint.
What does this mean in practice?
In most regulated procedures, animals will ultimately be killed for necessary scientific reasons (such as tissue collection) or because they cannot be released from the Act due to the procedures they have undergone. This planned, humane killing is not the same as an animal dying on its own during a procedure.
Under A(SP)A, an animal can only be released from the Act if:
– It has completed all regulated procedures required by the programme of work.
– It has fully recovered from those procedures.
– It is not suffering, and is not likely to suffer, as a result of those procedures.
– Its future welfare is not compromised by anything done under the licence.
If any of these conditions are not met, the animal cannot be released from the Act, and a humane killing procedure (Schedule 1 or a method authorised on the licence) must be carried out.
“Death as an endpoint” refers to an animal dying unexpectedly during a procedure.
This should always be prevented. Good monitoring, clear communication, and proactive management of adverse effects should allow animals to be removed from a study before they deteriorate to that point.
Finding an animal dead is not acceptable and suggests the animal may have experienced more suffering than was anticipated or allowed under the protocol.
How do I comply with PIL Standard Condition 7?
- Monitor your animals effectively and respond quickly to any signs of pain, suffering, or distress.
- Communicate with other PIL holders working on the same cohort.
- Listen to and act on observations from the animal care staff, who see the animals every day and often spot subtle changes early.
In many cases, this teamwork will allow you to apply an earlier humane endpoint and avoid unexpected deaths.
Some scenarios, such as certain genetically altered (GA) strains that naturally have higher mortality, are more challenging. Even then, reviewing your breeding data and understanding age-related risks helps you set defined, humane stopping points.
For example, if a GA line consistently shows mortality from around three months of age, you may decide that any non-experimental animals will be humanely killed at that age rather than risk unpredicted deaths. This is a form of refinement.
What resources are available to support me?
If you work with a severe model or any protocol with increased mortality risk:
- Discuss any animal deaths with the animal care team, NACWO, and Named Veterinary Surgeon.
- They may spot patterns or welfare indicators that you have not seen.
- Information gathered from these discussions can improve your humane endpoints and may also help you better understand disease progression in your model.
Balancing the need for viable animals with the need to avoid unnecessary suffering is challenging.
Consistently reviewing your data, clinical signs, life expectancy, breeding outcomes, and mortality patterns can significantly enhance your strategy and minimise overall harm.
Collaboration is key. The more openly you share and receive information from colleagues who work with your animals, the better you can manage the model.
What happens if I don’t comply with PIL Standard Condition 7?
- The unexpected death of an animal* is normally classified as “severe”, because we cannot determine exactly how much it suffered beforehand.
- This will usually require submitting a PPL Standard Condition 18 report.
- Higher-than-expected mortality rates may alert ASRU to welfare concerns and could trigger an investigation into potential non-compliance.
Animals will occasionally die despite our best efforts. What matters is how you respond. Treat every unexpected death as a learning point and an opportunity to improve refinement.
*If an animal was observed within an hour before being found dead, a post-mortem may allow the event to be assessed as less severe. Evidence for this is largely anecdotal.
How does ASRU assess compliance with PIL Standard Condition 7?
During an audit, inspectors may engage with NACWOs, NVS, PPL, and PIL holders to confirm training and competency in understanding humane endpoints. PPL and PIL holders may need to show proof of conversations between them about these endpoints.
How do I know if I am complying with PIL Standard Condition 7?
In an ideal world, you would never experience an unexpected animal death. In reality, almost everyone working with laboratory animals will encounter this at some point.
Success under Standard Condition 7 is shown by:
- consistently low levels of unexpected mortality
- clear documentation and investigation of any deaths that occur
- evidence that you have monitored and cared for animals as thoroughly as possible, and
- demonstrable learning and refinement following any incident.
The key takeaway is that you have done your best to monitor and care for the animal beforehand and can use this experience to help prevent similar issues in the future with other animals of the same strain or species.