Marine mammal euthanasia

Policy

Veterinarians attending a whale stranding or other emergency affecting free-living marine mammals (such as injury to animals or oil spills) have a duty of care to take all reasonable measures to ensure the survival and welfare of the animals.

Veterinarians may euthanase an animal if:

• in their opinion, the animal is injured or diseased or otherwise suffering, and
• there is reasonable belief that the injury, disease or other abnormality will cause the animal continued and excessive pain and suffering.

The method chosen for euthanasia should be at the discretion of the veterinarian, and must be rapid and humane. If this is not possible (for example, as is the case in some circumstances with large whales), then these animals should be left to die rather than have their suffering increased by inappropriate attempts to kill them.

This policy applies to all species of marine mammals - cetaceans (whales and dolphins) and pinnipeds (seals and sea lions).

Background

At various stages of marine mammal emergencies, the euthanasia of individual animals may be appropriate for one or more reasons:

• disabling injuries or gross impairment of physiological function
• dependency
  • abandoned newborn calves and orphaned suckling juveniles
  • just one or two survivors of a large, socially-interdependent group
  • where many or most of a herd have died, and the health status of a few survivors must be suspect
• strategic situations
  • a compromised, socially significant individual (i.e. the lead animal) has precipitated a mass stranding
  • some individuals harmed by stranding are deteriorating despite treatment and rehabilitation, and their continued presence prejudices the survival of the remainder
  • poor weather, lack of facilities or isolation prevents a rescue
• species considerations - for example, where an individual of a tropical species has strayed far outside its normal range.

Other indications include the following:

• Where a key (socially significant) animal precipitated the stranding and can be identified (i.e. the first animal ashore) and is found to be unfit, it may be euthanased to remove any possibility of its remaining a focus for the other animals and thereby compromising the rescue operation for those animals.
• A group of animals prepared for release to sea should not contain any individuals whose fitness has been compromised by the stranding experience, as these animals may be likely to come ashore again and jeopardise the survival of the remainder. Euthanasia may be the only humane option for unfit individuals, and, for animal welfare reasons, the sooner this is carried out the better.
• Those animals that repeatedly strand after release may need to be euthanased.

Veterinary ethics dictate that no veterinarian shall allow an animal to suffer unnecessary, unreasonable or unjustifiable pain. This is supported by animal welfare legislation in most jurisdictions. However, despite the clarity of the guidelines for euthanasia of marine mammals ¹, situations arise in which the decision to euthanase an animal is questioned.

Guidelines

The following guidelines should be observed for emergencies affecting marine mammals:

• The Australian Veterinary Association (AVA) recommends the guidelines for euthanasia presented by Warneke ¹ as a useful basis for making decisions about euthanasia at whale strandings.
• The decision to euthanase an animal must be made by the veterinarian. The decision is based on evaluation of all the circumstances, including a clinical appraisal of the animals involved. The incident controller and other relevant advisers should be consulted before the decision is made to euthanase an animal.
• The veterinarian who concludes that euthanasia of an animal is necessary should seek approval from the responsible state authority. In some jurisdictions, this may be mandatory.
• The veterinarian must ensure that only those animals with a reasonable chance of survival are treated for return to the sea. Every attempt must be made to alleviate the suffering of all other animals, including arranging for their prompt euthanasia.
• In some circumstances, healthy animals may need to be euthanased — for example, where a large number of animals have come ashore in an isolated location and there is no hope for their rescue, or dependent young are stranded.
• The AVA supports the use of lethal injection and/or a brain shot for euthanasia of small whales. It also supports an informed decision not to treat large whales if their situation is hopeless and no suitable method of euthanasia is available. It does not condone the use of asphyxiation or lancing for euthanasia of any cetacean species.
• The attending veterinarian should give appropriate professional advice and support to the state official responsible for management of the stranding event (the incident controller).
• If possible, animals should be physically identified in some way before their release, so that they can be monitored after release. This will be particularly useful if individuals come ashore again.
• As many as possible of those animals that die, including key animals, should be subjected to necropsy, to determine the cause of the stranding or of death.
• Attending veterinarians must collect sufficient records (including photographs) to report, publish and disseminate information, findings and experiences from each stranding event.

References

1. Warneke RM, editor. Victorian whale rescue plan: a contingency plan for strandings of cetacea (whales, dolphins and porpoises) on the Victorian coastline. Fisheries and Wildlife Service, Department of Conservation, Forests and Lands, Victoria, 1986.