Rhodesian Ridgeback Inherited Ventricular Arrhythmia (RR IVA) is an inherited disease that results in an abnormality of the cardiac electrical system leading to the development of abnormal heart beats (ventricular premature beats – VPCs). In some cases these abnormal heart beats can result in sudden death.  It appears that the most severe disease may be present between 6 and 30 months of age and many dogs appear to outgrow the problem.

A genetic mutation (QIL1) has been identified in association with the development of RRIVA.

RRIVA is a disease of incomplete penetrance. Presence of the mutation will not guarantee the development of RRIVA, and disease can still occur in the absence of the mutation. However, results from our genetic tests can be beneficial in guiding breeding practices and potential therapeutic measures.

Testing Prices:

Rhodesian Ridgeback IVA = $48.00 per dog

Rhodesian Ridgeback Litter Discount = $38.00 per puppy

Sample Type for Submission:

Acceptable samples include a cheek swab or 1-2 mL whole blood collected in an EDTA tube. If these sample types are unavailable, please reach out to us at cvm-cardiacgenetics@ncsu.edu for more information. Alternative sample types may result in an additional charge.

Holter Monitoring:

A 24 hour Holter monitor is a useful tool in Rhodesian Ridgeback IVA screening and monitoring. Holter monitoring is recommended for Rhodesian Ridgebacks between 3 months and 3 years of age. Holter monitors for Rhodesian Ridgebacks can be requested in combination with our genetic test or on its own without the genetic test. In addition, your veterinarian can request a diagnostic holter with our service which will provide interpretation from a veterinary cardiologist. For more information regarding holter monitoring, and directions on how to request this service, please visit – here

Explanation of Results:

Two copies of each gene are inherited, one from each parent. Possible results include:

Negative

Dogs have two copies of the normal gene, which is not predicted to be at an increased risk of RRIVA. They cannot transmit this mutation to their offspring.

Positive Heterozygous

Dogs have one copy of the normal gene and one copy of the mutated gene, which is associated with an increased risk of developing RRIVA.

Positive Homozygous

Dogs have two copies of the mutated gene, which is associated with an increased risk of developing RRIVA. They will transmit one copy of the mutation to their offspring.

Our current results suggest that about 60% of the dogs that are positive will develop a cardiac arrhythmia and may need treatment. Many dogs appear to outgrow the disease between 2 and 3 years of age. We recommend that dogs that are positive have a Holter monitor performed periodically between 6 months to 3 years of age.

Other factors could contribute to this condition in dogs, and a negative result does not rule out the presence of a different mutation that could cause a similar genetic disorder or trait.

Breeding Recommendations:

Breeding decisions should be made carefully and in discussion with your veterinarian. We cannot give specific breeding recommendations regarding your dog, but we advise to consider these genetic results as well as the overall health of the line. The goal is to reduce the prevalence of these disease-associated mutations while maintaining high quality variety within the population.