Objective assessment of chronic pain in donkeys using the donkey chronic pain scale (DCPS): A scale-construction study.

Assessment of chronic pain is very important for monitoring and improving welfare and quality of life in donkeys. Freedom from disease and pain is one of the 'five freedoms' underlying animal welfare. The aim of the current study was to develop a pain scale for assessment of chronic pain in donkeys (Donkey Chronic Pain Scale; DCPS), including behavioural and facial expression-related parameters.