Canine multifocal retinopathy 2 is an inherited disease in dogs affecting the retina. Changes are usually present in animals affected with CMR before 4 months of age and are characterized by small light-coloured lesions (retina) is separating/folding (10-14 weeks of age). These multifocal areas of retinal are typically found in both eyes and can appear gray, tan, orange or pink and vary in number, size and location. Vision loss is reported, but it seems some dogs do fairly well into old age, and some do not.
Canine multifocal retinopathy 2 is an inherited disease in dogs affecting the retina. The disease belongs to a group of inherited retinal disorders primarily caused by mutations scattered throughout the entire BEST1, a gene necessary for retinal pigment epithelium (RPE) function (CMR1, CMR2, CMR3). Salient fundus changes are usually present in animals affected with CMR before 4 months of age and are characterized by multifocal areas of retinal which in older dogs progress to multifocal areas of outer retinal atrophy. "Signs of cmr include multiple tan-pink subretinal patches in both the tapetal and the non-tapetal fundus along with focal areas of tapetal hyper-reflectivity. The lesions elevate the retina, progressing as the dog ages, to focal areas of retinal degeneration and retinal pigment epithelial hypertrophy and pigmentation" (Grahn et al., 1998).
Guziewicz, KE., Zangerl, B., Lindauer, SJ., Mullins, RF., Sandmeyer, LS., Grahn, BH., Stone, EM., Acland, GM., Aguirre, GD. : Bestrophin gene mutations cause canine multifocal retinopathy: a novel animal model for best disease. Invest Ophthalmol Vis Sci 48:1959-67, 2007. Pubmed reference: 17460247. DOI: 10.1167/iovs.06-1374.