Pain due lesions and clinical conditions is one of the main welfare concerns of the more than 42 millions donkeys that presently exist in the world. Yet, the knowledge to gauge pain in donkeys is lacking, misunderstood and/or not validated (Ashley, 2005).
Pain (yes/no/uncertain) and its severity (VAS; no pain=0 to worst pain=100mm) was assessed in 403 donkeys’ ante-mortem (ATM) and post-mortem (PTM). Also behaviours/signs (BS) and pain related lesions (PRL) were assessed ATM and PTM, respectively. Using principal component analysis the more than 53 BS and 238 PRL observed were narrowed to 58 biologically meaningful component or groups (14 BS and 44 PRL components, respectively). Components were used as risk factors in multiple regression analysis to identify which BS and/or PRL are commonly used in clinician’s (veterinary/pathologist) decision making process to determine whether a donkey ‘is’ (i.e. ATM) or ‘was’ (i.e. PTM) in pain and its severity (mild to severe). Furthermore, multiple correlations were made to understand which BS relate significantly with specific PRL and how.
A cross tabulation between pain ATM and PTM, where pain related lesions are used as a quasi-gold standard of pain assessment; identify that 2 in 10 donkeys are wrongly assumed as in NO-PAIN. Moreover, only 43% of the donkey observations are used by clinicians to make their opinion on donkey pain and its severity (i.e. 7 BS and 18 PRL components were significantly associated with pain as stated by clinicians). Yet, multiple correlations showed 20 plausible biologically meaningful relationships between BS and PRL; some currently not used by clinicians.
This methodology, previously successfully used in humans (Gregory, 2010) is novel to donkey veterinary medicine and warrants further research to consolidate findings. Nonetheless, the achieved correlation list of behaviours vs. pathologies is a significant work with valid applications in donkey pain identification and prognosis.
Ashley FH, Waterman-Pearson AE, Whay HR (2005) Behavioural assessment of pain in horses and donkeys: application to clinical practice and future studies, Equine Vet J, 37(6), 565 - 575.
Gregory NG (2010) Relationships between pathology and pain severities: a review. Animal Welfare 19, 437-448.