Juvenile ocular abnormalities in a litter of black-footed ferrets

To describe the clinical and histopathological features of ocular abnormalities noted in a litter of black-footed ferrets (Mustela nigripes), including corneal opacification, cataracts, persistent pupillary membranes, microphthalmia, symblepharon and anterior segment malformation.

A litter of eight black-footed ferrets examined at 10 weeks old with a history of ophthalmia neonatorum first noted at 7 days old and histopathological examination of three globes from three ferrets of the same litter between 5 and 7 months old following routine subconjunctival enucleation.

Due to the fractious nature of black-footed ferrets, slit-lamp biomicroscopic examination was performed under general isoflurane anesthesia at 10 weeks of age. Corneal opacification was noted in 9/16 eyes, cataracts in 4/16 eyes, and persistent pupillary membranes in 3/16 eyes, among other findings. Histopathology revealed persistent pupillary membranes and Descemet's membrane abnormalities consistent with congenital anterior segment malformation in all three globes. In one ferret, a posterior cortical cataract with posterior lenticular malformation and lens capsule discontinuity was noted. Purulent discharge was cultured at time of enucleation in one ferret with growth of E. coli.

A novel constellation of ocular malformations with primary congenital and secondary to ophthalmia neonatorum etiologies is described in black-footed ferrets. Due to endangered status of black-footed ferrets, small genetic pool and the requirement for adequate vision for wild-release, congenital ocular abnormalities such as anterior segment malformation and likely the cataracts described are of particular concern. Further investigation and monitoring are warranted to determine the heritability of these ocular abnormalities.