The Importance of Refining Anaesthetic Regimes to Mitigate Adverse Effects in Very Young and Very Old Wild Animals: the European Badger (Meles Meles)

Safe and effective anesthesia is vital to the welfare of animals used in laboratory and field research, yet very young and very old animals may benefit from refinements to standard protocols and the therapeutic mitigation of adverse effects. Here we report rare but important instances of adverse effects across a sample of 11,645 anesthesia procedures, involving 1806 individual European badgers (1987-2018). Small cubs (<2.3 kg) benefitted from being administered just 50% of adult anaesthetic dose rates, else a proportion were at risk of exhibiting protracted recovery from sedation. These individuals responded well to treatment with a glucocorticoid (0.1 mg/kg Dexadreson® / dexamethasone). Females older than 8 yrs were susceptible to seizures, treatable with benzodiazepines (0.2 mg/ kg midazolam). We advise that practioners working with less familiar wild species are alert to these kinds of welfare risk factors and have appropriate treatment on hand to alleviate adverse effects.

Keywords: Anesthesia, Adverse effects, European badger, Geriatric, Cubs, Seizures.