Notes on the health status of free-living, non-native American mink, Neovison vison, in southern England

Haematological and serum biochemistry values were determined for 13 adult, free-living American mink, Neovison vison, in southern England live trapped as part of a longer term research project. Serum samples were tested for the presence of antibodies against Toxoplasma gondii, Aleutian disease virus (ADV) and canine distemper virus (CDV). Animals were examined to assess ectoparasite burden; faecal samples were examined for the presence of gut parasites and bacteria (identified via culture). Post-mortem examinations were carried out on four individuals shot during on-going control operations. Haematological and serum biochemistry values for most individuals were similar to published values for captive mink. Neutrophil/lymphocyte ratios were high in two animals (possibly due to trap-associated stress). Three individuals had high levels of creatinine, urea and the liver enzymes, alanine transaminase, aspartate transaminase, alkaline phosphatise and gamma-glutamyl transpeptidase. Six of 12 mink tested positive for antibodies to T. gondii and 8 of 12 tested positive for antibodies to ADV; none tested positive for antibodies to CDV. No significant bacteria or parasites were detected in faecal samples. Post-mortem examinations in three cases showed no significant lesions but the fourth animal had Skrjabingylus nasicola nematodes in the nasal passages, lung lesions suggestive of adiaspiromycosis, cholangiohepatitis possibly indicative of Pseudamphistomum truncatum infection and tubulointerstitial nephritis associated with renal calculi.