In many situations choices must be made that will have an impact on the welfare of companion animals. Often one of the options will be to euthanase the animal in question. The way in which one views this option will depend not only on one's assessment of the quality of the animal's life (or the lives of other affected parties), but also on how one values an animal life as such. Clearly, a companion animal may be valued by a human being or by another animal. A dog's death may affect its owner's quality of life (QoL), or it may affect the QoL of other animals in the household. But does the life of an animal have any value other than that? Is anything lost, for example, when a dog that lived with a sole owner, now deceased, is euthanased? Conversely, would anything be gained if the dog were re-homed (apart from the potentially positive contribution to the new owners' QoL)? More generally, in prolonging, or refraining from ending, the life of an animal, is it thereby ensured that something of value persists? There seem to be three main views on this matter. The first is that animal life has no value in itself. The second is that animal life has value to the extent that the life in question is worth living for the animal. The third view is that the life of an animal has a value that exceeds what is ‘in it’ for the animal in question. The view one accepts here will have a dramatic impact on one's attitude to many of the choices to be made about the treatment of companion animals — choices in which one must balance quality of life against, as it were, quantity of life. So the heart of the matter is not only quality of life. It is also value of life. Unfortunately it may prove much more difficult to agree about the value of animal life than it is to agree about the significance of animal welfare.