Fatal bacterial septicaemia after immobilisation of a captive brown bear (Ursus arctos)

A four-year-old female brown bear (Ursus arctos) was immobilised via blowpipe targeting the right hind limb to perform a chemical contraception. Few days after anaesthesia, the animal developed lameness and a reduced general condition, and died 1 week after immobilisation when alopecia and swelling of the injection area were observed for the first time. Besides a severe azotaemia, alopecia and reddening of the craniomedial skin, subcutis and skeletal muscles of the entire right hind limb showed a phlegmon, oedema and haemorrhage. Additional widespread haemorrhages were found. Histology revealed a suppurative and necrohaemorrhagic myositis of the affected limb, a suppurative iliofemoral lymphadenitis, blood resorption in the mesenteric lymph nodes and haemorrhage in the adrenal gland cortex. Microbiological investigation revealed high amounts of Escherichia coli, Streptococcus dysgalactiae and Clostridium septicum in skin, musculature, heart, lung, liver and spleen, indicating septicaemia, which led to death due to toxaemic shock.