Characterization of brain lesions in Danish farm mink (Neogale vison) with acute, fatal SARS-CoV-2 infection

The pathology of brain tissue from 13 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected mink (Neogale vison), 20 mink in recovery, as well as 16 uninfected mink were investigated by histology and immunohistochemistry (IHC), contributing to the limited knowledge on brain pathology in mink. IHC and histology did not reveal direct viral infection in the brain tissue, but evidence of fibrin microthrombi were frequently found in the acute fatally infected mink, without associated ischaemic injury or inflammation. This finding does not align with observations in brains of human COVID-19 patients, as the mink lacked the ischaemic and inflammatory lesions commonly associated with the cerebral microthrombi observed in human studies. Neither fibrin microthrombi nor ischaemic or inflammatory lesions were observed in the brain of recovering mink.