Case 3 180817 (outside)
Conference Coordinator: Dr Molly Liepnieks.
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Adult, female American crow (Corvus brachyrhynchos)
The bird was found down and it was immediately euthanized.
The keel is prominent with loss of pectoral musculature (poor body condition). The left air sacs (from caudal to cranial) are thickened with yellow, dry material covering the surfaces. The right foot has two 0.5-1 cm diameter exophytic, rough masses.
The epidermis of this skin section is focally, markedly expanded by exophytic fronds of hyperplastic squamous epithelial cells (stratum spinosum and stratum corneum) with moderately hyperplastic strata granulosum and basale. Almost all epithelial cells contain large, darkly eosinophilic intracytoplasmic inclusions. Some of the epithelial cells have prominent intracytoplasmic and intercellular clear spaces (edema). The underlying dermis has moderate fibrosis and mild perivascular lymphoplasmacytic inflammation. The superficial portions of the masses have bacterial colonies and fungal hyphae.
No special stains.
Skin: Multifocal epidermal hyperplasia with poxviral inclusions (Bollinger bodies).
Avian poxviruses are classified in the genus Avipoxvirus; they can result in ‘dry’ or cutaneous pox or diptheritic or ‘wet’ pox. The case presented her is consistent with the cutaneous manifestation. Characteristic lesions of the cutaneous form of pox include epidermal hyperplasia and large eosinophilic intracytoplasmic viral inclusions (Bollinger bodies/inclusion bodies). Transmission occurs via mosquito, aerosols, and/or direct transmission in injuries.
Jubb, K. V. F., Peter C. Kennedy, and Nigel Palmer. Pathology of Domestic Animals. St. Louis, MO: Elsevier, 2016. Print.
