It was diagnoised in a kingsnake and in vipers. "Syndromes closely resembling inclusion body disease have occasionally been diagnosed in ‘non-Boidae’. A case in young corn snakes (Pantherophis guttatus guttatus, family Colubridae) was described by Fleming and others (2003), and a histological examination revealed eosinophilic intracytoplasmic
inclusions, but no retrovirus-like particles were found by electron microscopy."

Source: https://netfiles.uiuc.edu/doortiz2/www/IBD.pdf