Canine and Feline Models of Inherited Retinal Diseases

Naturally occurring inherited retinal diseases (IRDs) in cats and dogs provide a rich source of potential models for human IRDs. In many cases, the phenotypes between the species with mutations of the homologous genes are very similar. Both cats and dogs have a high-acuity retinal region, the area centralis, an equivalent to the human macula, with tightly packed photoreceptors and higher cone density. This and the similarity in globe size to that of humans means these large animal models provide information not obtainable from rodent models. The established cat and dog models include those for Leber congenital amaurosis, retinitis pigmentosa (including recessive, dominant, and X-linked forms), achromatopsia, Best disease, congenital stationary night blindness and other synaptic dysfunctions, RDH5-associated retinopathy, and Stargardt disease. Several of these models have proven to be important in the development of translational therapies such as gene-augmentation therapies. Advances have been made in editing the canine genome, which necessitated overcoming challenges presented by the specifics of canine reproduction. Feline genome editing presents fewer challenges. We can anticipate the generation of specific cat and dog IRD models by genome editing in the future.