In this paper I describe a hypothetical strategy for assessing poor and good welfare with the aim of making a judgement about an animal's quality of life. The concepts discussed here may also contribute to the notion of what makes ‘a life worth living’. The strategy involves attributing scores to positive and negative aspects of an animal's well-being, using predefined categories and a simple scoring rote, and then summating these scores into an overall welfare score. The strategy incorporates a mathematical calculation that has certain mathematical biases to help ensure that any animal suffering is not excessive. I draw attention to some limitations of the proposed strategy and stress that such mathematical scoring systems cannot be used simplistically. Nevertheless, the proposed strategy could be refined, tested and validated to assist decision-making by those with a duty of care to the animal concerned.
