Microscopic evidence of adenoviral infection in a muskrat in Illinois

A wild muskrat (Ondatra zibethicus) found moribund in Illinois (USA) had mi nimal meningitis and pleuritis, probably of bacterial origin. There were la rge, basophilic, intranuclear inclusion bodies within scattered enterocytes . The inclusions were microscopically typical of those produced by adenovir uses, and ultrastructurally were intranuclear paracrystalline arrays of vir us particles with characteristics of adeno-viruses. The significance of the adenovirus infection in this muskrat is unknown.