Quality-of-Life Assessments in Zoo Animals: Not Just for the Aged and Charismatic

SIMPLE SUMMARY: Zoos should aim to provide all of their animals with a good quality of life throughout life. Although quality of life is a complex notion that is difficult to define and measure, some modern zoos and zoo industry associations have started to develop and implement formalized quality-of-life assessment tools for this purpose. These tools have been used predominantly to assess the health and welfare of geriatric zoo mammals to assist in decision-making in relation to end-of-life care, including the timing of euthanasia. There is scope to improve the accuracy of these tools and to extend their use to assess the quality of life of non-mammalian species (e.g., birds and reptiles) and animals at other life stages (e.g., young adults) to enhance animal welfare. This review summarizes what quality of life is, why and how we should assess it in zoo animals, and what challenges this poses. It also identifies some learnings from quality-of-life assessments in humans and domestic species that can be applied to zoo animals and suggests directions for future innovations in this field. ABSTRACT: Zoos should aim to provide all of their animals with a good quality of life (QoL) throughout all life stages. In parallel with the evolution of QoL assessment questionnaires and tools in human and domestic animal settings, in recent times, some individual zoos and zoo industry associations have incorporated such instruments into their animal management practices. This has been conducted predominantly to inform, monitor, and document end-of-life decision-making for large, charismatic mammals. There is scope to expand the use of these tools to improve their utility, validity, reliability, and value to an animal welfare program. Assessment of QoL is a complex task given that the notion being measured is abstract and self-determined, and the design and purpose of the tools to do this require careful consideration. This review explores the QoL concept as it applies to animals, the assessment indications and methodologies relevant to a zoo setting, and the importance of considering QoL at any life stage across species. An overview of current thinking and the applications and limitations of QoL evaluation of captive wild animals is offered to promote and aid facility practice reviews and to help direct future innovations that leverage concurrent and converging advances in zoo animal welfare science.