Long-term Pathological Survey of Icelandic Rock Ptarmigan (Lagopus muta); Renal, Dermatological, and Traumatic Lesions

Pathological findings in wild birds are rarely reported. This paper reviews gross and histological findings in samples from Icelandic rock ptarmigan (Lagopus muta), obtained through both systematic and lesion-based organ sampling. The study was part of larger project in which ptarmigan were collected and dissected over a 13- year period to study health and population changes. The primary pathological conditions identified were mange and renal tubular oxalosis, with prevalences of 18.3% and 25.3%, respectively. Mange resulted from skin mite infestations, which were more common in juveniles than in adults and more prevalent in females than males. The sex difference was attributed to a higher prevalence in adult females compared to adult males. The prevalence of renal tubular oxalosis did not vary by age or sex, but juveniles exhibited higher average severity scores for the condition than adults. Despite coccidia being found in faecal samples and in histological sections of the intestine, negligible histopathological lesions were seen in the intestinal mucosa. Lesions due to trauma showed a notably high prevalence of 2.6%. The study highlights the importance of histological examination of organs from hunter-collected specimens.