Kansas State Veterinary Diagnostic Laboratory, Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
Lysosomal storage diseases are uncommon in avian species. Cases of confirmed lysosomal storage diseases are reported in emus, Costa’s hummingbirds, and Humboldt penguins.1-4 Three adult nēnē or Hawaiian geese (Branta sandvicensis) in the same exhibit of a Kansas zoo presented for generalized ataxia and tremors. Clinical signs began during their molt and were progressive, the birds were euthanized within 6 weeks of onset of clinical signs for declining neurologic condition. Radiographs were taken approximately 3 weeks prior to death and revealed no evidence of metallic foreign bodies or other radiographic abnormalities. The birds had no significant gross lesions noticed on gross necropsy examination. Histopathological examination with hematoxylin and eosin stain revealed swollen neurons within the grey matter that often contained foamy, amphophilic cytoplasm that displaced the nucleus peripherally. To further classify material within the cytoplasm, periodic acid Schiff (PAS), Ziehl-Neelsen, luxol fast blue, alcian blue special staining was performed. The accumulation of material in the neurons did not stain with any of the special staining performed. On electron microscopy, there were concentric lamellar stacks or “zebra bodies” were observed with features consistent with sphingolipidoses and mucopolysaccharidoses that were previous reported in birds.3,4 To the author’s knowledge, this is the first confirmed lysosomal storage disease in an Anseriform.
The authors would like to thank the Kansas State Veterinary Diagnostic Lab, Nanotechnology Innovation Center of Kansas State (NICKS) and the Emporia Zoo.
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