How to preserve quality of life in the ageing canine: in-home modification and nutritional supplements

The question of what is quality of life (QoL) is a deep philosophical matter that has been debated since ethics began (Yeates and Main, 2009). The World Health Organisation (WHO) (1995) defined the concept of human QoL to include an individual's perception of their position in life, including the context of culture, their value systems, goals, expectations, standards and concerns. QoL is often attributed to physical health alone; the WHO definition makes explicit the importance of other factors in determining an individual's perception of their general ‘enjoyment of life’.

As animals are incapable of ‘individual perception’, this significantly complicates matters when attempting to define their QoL (Niessen, 2011). Yeates and Main (2009) suggested animal QoL is best approached by first deciding what is important for the animal, and second by working out what can be assessed for use in decision making. This requires a combination of assessing those qualities of life from the animal's point of view and the assessment from the observer's point of view. Animal QoL includes the ‘feelings’ of the animal which can be broadly classified as pleasant or unpleasant. Using the analogy of balance scales, QoL can be improved by increasing the pleasant feelings and decreasing the unpleasant ones.