Hereditary rod-cone degeneration in a strain of Abyssinian cats.

The retinal disease found in this strain of Abyssinian cats is a heritable disorder, primarily affecting the photoreceptors. The retina is, in most cases, ophthalmoscopically normal until the age of 1.5-2 years. The retinal changes that then appear are slowly progressive and lead to a generalized retinal atrophy in another 2-4 years. It is obvious that this cat retinal degeneration shows many similarities to human Retinitis Pigmentosa. Just as in RP the midperiphery/periphery is most severely affected at the earlier stages, and with progression of disease alterations become generalized, the central retina being the best preserved area until the very late stage. Rods are affected prior to cones, but later in the disease there is an involvement of both rods and cones. Also, the disease process is slow, starting off from an ophthalmoscopically normal appearing retina. This strain of Abyssinian cats, affected by the presently described retinal disease, therefore has the potential of becoming a new animal model in the study of hereditary visual cell disease processes.