Read the Spanish translation: Enfermedad Asociada a Astrovirus en Ardillas Grises Huerfanas (Sciurus carolinensis)
Astrovirus was identified in orphaned grey squirrels (Sciurus carolinensis) being hand-raised at a wildlife rehabilitation center. A group of 14 squirrels became acutely ill with bloating, depression, nausea, and severe mucoid diarrhea. Serial fecal tests yielded no parasites; cultures from fecal samples, rubber feeding nipples, bowls, and the formula used for feeding revealed no GI pathogens. All affected squirrels were treated with metoclopramide, subcutaneous fluids, trimethoprim-sulfamethoxazole or metronidazole, and simethicone gas drops. Twenty-one percent (3/14) died within 24 hours of onset of signs. The remaining squirrels improved within 4 days and were clinically normal within 10 days. During a postmortem necropsy, astrovirus particles were found by electron microscopy in samples of intestine from one squirrel, as well as in fecal samples submitted from other affected squirrels. Consensus PCR and sequencing of these fecal samples revealed two distinct novel astroviruses in the genus Mamastrovirus, one of which was found in all animals tested. Astroviruses are a family of RNA viruses that have been identified in various mammal species as well as several avian species.1,3 Human astrovirus is one of the leading causes of diarrhea in infant humans and turkey astroviruses cause low growth rates in affected turkey poults.1,3 By inducing an increase in epithelial barrier permeability, astroviruses cause severe mucoid diarrhea in the absence of significant histopathologic changes.2,4 The clinical signs exhibited by this group of squirrels are similar to those seen in other species, although with a higher mortality rate. To our knowledge, astroviruses have not previously been identified in grey squirrels.
The authors would like to thank the medical and nursery staff at the SPCA Wildlife Care Center for their assistance in the care and treatment of the affected squirrels.
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4. Moser, L.A., M. Carter, S. Schultz-Cherry. 2007. Astrovirus increases epithelial barrier permeability independent of viral replication. J of Virology. 81:11937–11945.