PRIORITY BIOPSY W/DESC (1 SITE)
1-month-old male Flamingo. Multiple lesions foot and hock. Lesion submitted from hock.Click here for the IDEXX Pathology Report on this case.
Three fragmented sections of non-feathered skin from the hock region are examined, revealing diffuse severe irregular epidermal hyperplasia, characterized by pseudoepitheliomatous proliferation of the epidermis (primary acanthosis and basal cell hyperplasia). Many of the proliferating keratinocytes contain large, hypereosinophilic, solid to ring-like, intracytoplasmic inclusion (Bollinger) bodies. Fewer keratinocytes display ballooning degeneration. There is multifocal erosion and necrosis of the epidermis, associated with serohemorrhagic and cellular crust formation. There is moderate heterophilic inflammation associated with the hyperplastic epidermis and the in subjacent dermis.
Non-feathered skin (hock), proliferative and necrotizing dermatitis, diffuse, marked, subacute to chronic-active with heterophilic inflammation, intracytoplasmic eosinophilic inclusion bodies, and ballooning degeneration (highly suggestive of poxvirus infection).
I reached out to fellow IDEXX pathologists Dr. Alison Righton, Dr. Amanda Dennis, and Dr. Kelly Keating. My following comment incorporates our consensus opinion for this interesting case.
Histologic findings are highly suggestive of poxvirus infection in this 1-month-old flamingo. This is a rare infection in flamingos, and we could only find one documented report of poxvirus infection in 30% of fledglings in a flock of Lesser flamingos in South Africa. In this report, lesions presented as nonpigmented raised plaques on the legs and bills. However, the lesions were ultimately self-regressing, without any significant mortality reported. The exact identity of the poxvirus was not determined, but has similarity to poxviruses isolated from albatrosses and falcons.
Please note, that as far as we are aware, that there are no documented cases of poxvirus infection in flamingos in the US. If you have not done so already, I would suggestive sampling/banking any other similar lesions at -80 degrees Celsius (in case PCR and/or virus isolation is necessary).