Which method is suitable for killing foetal and embryonic animals?

The method suitable for killing fetal and embryonic animals is an overdose of anesthetic. This approach is consistent with veterinarians' ethical considerations and standards for euthanasia. An overdose of anesthetic ensures that the process is humane, minimizing stress and suffering for the animals involved. It allows for a more controlled and gentle approach, which is particularly important when dealing with animals at a very vulnerable stage of development.

Other methods may not provide the same level of assurance in terms of humane treatment and could be inappropriate for the specific developmental state of fetuses or embryos. While electrocution, immediate euthanasia, or standard euthanasia methods might be suitable in different contexts, they could raise ethical concerns, potentially cause unnecessary suffering, or be more suited to fully developed animals rather than embryos or fetuses.