Multifocal Retinopathy 3 (CMR3)

Canine multifocal retinopathies (CMR) are a group of inherited eye diseases. The diseases were reported in mastiff-related breeds (CMR1), Coton de Tulear (CMR2) and in Lapponian herder (CMR3). CMR1 is found in different dog breeds, whereas CMR2 and CMR3 are so far exclusive to a single dog breed each. While exhibiting similar clinical symptoms comparable to CMR1 and CMR2, CMR3 is predicted to be based on a distinctly different molecular mechanism. CMR3 manifests in grey, tan or pink subretinal fluid in the eye, retinal elevations and generalized progressive retinal atrophy. The age of onset of the multifocal retinopathy ranges from 9 months to 2 years. Some of the individual lesions can disappear over time. The majority of CMR3 affected dogs have a typical CMR phenotype, while some can develop a more indistinguishable phenotype from multifocal retinal dysplasia or generalized retinal degeneration.

Inheritance: autosomal recessive

Mutation: BEST1 gene

Genetic test: The method used for testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs. Testing can be done at any age.