Canine Multifocal Retinopathy 1 (CMR1)

Quick Summary

Canine multifocal retinopathy 1 is an inherited eye disease characterized by areas of retinal detachment. The disease does not typically lead to blindness or vision deficits.

Click here for Price and Turnaround Time

Phenotype: 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.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal, CMR1 = Canine multifocal retinopathy 1

Breeds appropriate for testing: American Bulldog, American Bully, Aussiedoodle, Australian Koolie, Australian Shepherd, Brazilian Terrier, Bulldog, Bullmastiff, Cane Corso, Dogue de Bordeaux, English Bulldog, English Mastiff, French Bulldog, Great Pyrenees, Havanese, Koolie, Mastiff, Miniature American Shepherd, Miniature Australian Shepherd, Olde English Bulldogge, Perro de Presa Canario, Shorty Bull, South African Boerboel, Toy Australian Shepherd

Explanation of Results:

  • Dogs with N/N genotype will not have canine multifocal retinopathy 1 and cannot transmit this CMR1 variant to their offspring.
  • Dogs with N/CMR1 genotype will not have canine multifocal retinopathy 1, but are carriers. They will transmit this CMR1 variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% canine multifocal retinopathy 1-affected puppies.
  • Dogs with CMR1/CMR1 genotype will develop canine multifocal retinopathy 1, an eye disease, and will transmit this variant to all of their offspring.

Results of this test can be submitted to the OFA (Orthopedic Foundation for Animals)

Turnaround Time
At least 15 business days; may be delayed beyond 15 business days if sample requires additional testing, or a new sample is requested.
Price

$55 single test per animal ($5 discount on 3 or more dogs)

$25 as additional health test on same animal

Sample Collection

Dog DNA tests are carried out using cells brushed from your dog's cheeks and gums. The preferred cytology brushes are sent to you by mail, or you may provide your own brushes. For accepted alternative brushes, click here

We recommend waiting until puppies are at least three weeks old before testing.

 

Dog having its cheeks and gums brushed for DNA samples
Cheek and gum brushing technique for canine DNA sample collection

Step-By-Step:

  1. Make sure the dog has not had anything to eat or drink for at least 1 hour prior to collecting sample.
  2. When swabbing puppies, isolate each puppy from the mother, littermates and any shared toys for 1 hour prior to swabbing. Puppies should not have nursed or eaten for 1 hour prior to collecting sample.
  3. If collecting samples from more than one dog, make sure to sample one dog at a time and wash your hands before swabbing another dog.
  4. Label brush sleeve with name or ID of dog to be sampled.
  5. Open brush sleeve by arrow and remove one brush by its handle.
  6. Place bristle head between the dog’s gums and cheek and press lightly on the outside of the cheek while rubbing or rotating the brush back and forth for 15 seconds.
  7. Wave the brush in the air for 20 seconds to air dry.
  8. Insert brush back into sleeve.
  9. Repeat steps 5 - 8 for each unused brush in sleeve on a fresh area of cheek and gums. Make sure to use and return all brushes sent by the VGL. In most cases, it will be 3 brushes per dog. If using interdental gum brushes, please note that the VGL requires 4 brushes per dog and only moderate or wide interdental gum brushes are accepted.
  10. Do not seal brushes in sleeve.
  11. Place all samples in an envelope and return to the address provided.

ATTENTION:

  • Do not collect saliva/drool – the key to obtaining a good sample is getting cheek cells on the swab
  • Do not rub swab on the dog’s tongue or teeth – this will result in poor quality sample
  • Do not collect a sample from a puppy that has recently nursed – the mother’s genetic material can rub off on the puppy’s mouth and contaminate the sample
Additional Details

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% affected pups.

The VGL offers genetic tests for CMR1, CMR2, and CMR3 mutations. Genetic screening helps breeders establish the genetic status of breeding stock and select mating pairs appropriately in order to reduce the risk of producing affected offspring.

 

Note: CMR1, CMR2, and CMR3 mutations have different breed origins and distributions and thus test selection needs to be breed-appropriate. See "Breeds appropriate for testing" list on each page.