Canine Multifocal Retinopathy CMR1 CMR2



New Canine Test

Cocoa/French Bulldog Chocolate
Please see: Cocoa

New Equine Test

New test available for Quarter Horses and related breeds.
Please see: Immune-Mediated Myositis (IMM)

Equine Test

Equine Speed and Distance
Please see: Performance Testing

Canine Multifocal Retinopathy Type 1 and Type 2 (CMR1 and CMR2)


Canine Multifocal Retinopathy Type 1 and 2 (CMR1 and CMR2) is an autosomal recessive eye disorder known to affect Great Pyrenees, English Mastiffs, Bullmastiffs, Australian Shepherds, Dogue de Bordeaux, English Bulldogs, American Bulldogs, Coton de Tulears, Perro de Presa Canario, and Cane Corsos.


The mutation causes raised lesions to form on the retina. The lesions alter the appearance of the eye but usually do not affect sight. The lesions may disappear, or may result in minor retinal folding. Symptoms of the mutation usually appear when a puppy is only a few months old, and generally do not worsen over time.


CMR is a recessive disorder. This means that a dog must inherit two copies of the mutation in order to exhibit symptoms of CMR. A dog with one copy of the mutation is known as a carrier. If two carriers are bred to one another, there is a 25% chance per puppy born that they will develop symptoms of CMR and a 50% chance per puppy born that they will also be carriers. Therefore, it is useful to test for the presence of the CMR mutation before breeding. Additionally, since retinal defects can be caused by other conditions, testing can verify that a dog actually has CMR rather than some other eye condition.

Sample Type:

Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Sample collection kits are available and can be ordered at Canine Test Now.

Test Is Relevant to the Following Breeds:

There are two types of CMR: CMR1 and CMR 2. They both have similar symptoms. Animal Genetics offers testing for CMR1 and CMR2. Animal Genetics can test for CMR1 in the following breeds:

  • Great Pyrenees
  • English Mastiffs
  • Bullmastiffs
  • Australian Shepherds
  • Dogue de Bordeaux
  • English Bulldogs
  • American Bulldogs
  • Perro de Presa Canario
  • Cane Corsos
  • French Bulldogs


Animal Genetics offers CMR2 testing in the following breeds:

  • Coton de Tulears


Animal Genetics offers DNA testing for Canine Multifocal Retinopathy Types 1. The genetic test verifies the presence of the recessive mutation and presents results as one of the following:

CMR/CMR Affected The dog carries two copies of the mutant gene and is homozygous for CMR. This dog will be affected and will always pass on a copy of the mutated gene to its offspring.
CMR/n Carrier Both the normal and mutant copies of the gene detected. Dog is a carrier for the CMR mutation and can pass on a copy of the defective gene to its offspring 50% of the time.
n/n Clear Dog tested negative for the gene mutation that causes CMR and will not pass on the defective gene to its offspring.