UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory

Canine Multifocal Retinopathy 1

Canine Multifocal Retinopathy 1 (CMR1) is an inherited eye disease caused by a mutation (c.73C>T) in the Bestrophin 1 gene that results in a shortened, dysfunctional protein. Affected dogs typically present with multiple, discrete circular areas of retinal detachment between 11 and 16 weeks of age. Fluid accumulates under the detached retina resulting in gray, tan, orange or pink “blisters” in the eye. Progression of retinal changes is slow, ceases by 1 year and does not lead to blindness. In some cases, the blisters appear to heal as the dog ages but vision loss has been reported. The disease is inherited in an autosomal recessive fashion thus two copies of the CMR1 mutation must be present to produce the disease. Breeding two carriers is predicted to produce 25% of affected pups

The VGL offers a genetic test for the CMR1 mutation. Genetic screening helps breeders establish the genetic status of breeding stock and select mating pairs appropriately in order to reduce the risk of producing CMR1-affected offspring.

Testing is recommended for: American Bulldog, American Bully, Aussiedoodle, Australian Koolie, Australian Shepherd, Brazilian Terrier, Bulldog, Bullmastiff, Cane Corso, Dogue de Bordeaux, French Bulldog, Great Pyrenees, Havanese, Koolie, Mastiff, Miniature American Shepherd, Miniature Australian Shepherd, Perro de Presa Canario, Shorty Bull, South African Boerboel, Toy Australian Shepherd

Allow 5-10 business days for results.

Results reported as:


Normal - no copies of the CMR1 mutation


Carrier - 1 copy of the CMR1 mutation; dog is normal


Affected - 2 copies of the CMR1 mutation; dog will develop multifocal retinopathy


Gornik KR, Pirie CG, Duker JS, Boudrieau RJ. 2014. Canine multifocal retinopathy caused by a BEST1 mutation in a Boerboel. Vet Ophthalmol 17(5):368-72. [PubMed: 23998685]

Donner J, Kaukonen M, Anderson H, Moller F, Kyostila K, Sankari S, Hytonen M, Giger U, Lohi H. 2016. Genetic Panel Screening of Nearly 100 Mutations Reveals New Insights into the Breed Distribution of Risk Variants for Canine Hereditary Disorders. PLoS One 11(8). [PubMed: 27525650]

Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL