Müller K, Schettler E, Gerlach H, Brunnberg L, Hafez HM, Hattermann K, Johne R, Kollmann R, Krone O, Lierz M, Linke S, Lueschow D, Mankertz A et al. (2007): Investigations on the aetiology of pinching off syndrome in four white-tailed sea eagles (Haliaeetus albicilla) from Germany
Avian Pathol. 36 (3): 235-243.

The purpose of this study was to investigate the aetiology of the pinching off syndrome (POS), a generalised feather abnormality affecting free-living fledglings of the white-tailed sea eagle (Haliaeetus albicilla) (WTSE) in Europe. For the first time, extensive clinical, haematological, biochemical, virological, bacteriological, nutritional, histopathological, parasitological and electron microscopical examinations were performed on three females and one male suffering from POS. Early and increased cytokeratin formation at the base of regenerating feathers and their follicle was observed in affected birds. Ultrathin sections of the feather papillae revealed an extended stratum transitivum and a compact, thickened keratinised stratum corneum. The transitional cells in POS feathers contained vacuoles often associated with the nucleus. Lipofuscin accumulations in neurons, glia cells and islet cells of the pancreas were found in all examined birds. It was not clear if there is an association between the occurrence of lipofuscin and POS. No evidence that infectious agents (parasites, bacteria, fungi or viruses), malnutrition or hormonal imbalances are involved in the aetiology of POS in WTSEs. It remains unclear whether there is a genetic background of POS