*SAS = Sub-Aortic Stenosis
*PS = Pulmonic Stenosis
(All SAS and PS heart certifications are done via colour-Doppler)

**ARVC = Arrythmogenic Right Ventricular Cardiomyopathy
(all ARVC certifications are done as DNA tests in the USA)

NEG = Negative for the mutated gene
POS HET = Heterozygous Positive for the mutated gene (1 normal copy and 1 mutated copy of the gene)
POS HOM = Homozygous Positive for the mutated gene (2 mutated copies of the gene)

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a fairly common form of heart disease in the Boxer dog. It is inherited and NCSU College of Veterinary Medicine’s laboratory has identified a mutation responsible for the gene in some Boxers. However, it should be noted that in human beings with the same disease, there are many different genetic mutations which can cause this disease. We do not yet know if this is the only mutation in the Boxer or if there will be many different mutations. Please keep in mind that we are continually learning about this disease and recommendations will be altered as we obtain more information.

Currently the interpretation of the test is:

NEGATIVE RESULTS:
The absence of the mutation in this dog, does not mean that it will never develop the disease. It means that it does not have the only known mutation that can cause the disease in the dog at this time.

POSITIVE RESULTS:
Dogs that are positive for the test will not necessarily develop significant heart disease and die from the disease. Some dogs will develop a very mild form of the disease and will live quite comfortably, some may need treatment.

At this stage a witch hunt aimed at also removing all close relatives of Boxers diagnosed with ARVC could have a very serious negative impact on the diversity of our already limited gene pool and could aggravate other conditions, such as cancer, for which no screening tests are available.

According to Dr Kathryn Meurs (discoverer of the ARVC mutant gene), there may even be reasons for keeping in the breeding population some affected homozygous dogs (with two copies of the defective gene), if such dogs are healthy in every other way. She suggests:

Boxers that are heterozygous positive, or have one copy of the mutated gene and one normal gene, should be carefully evaluated for signs of disease using Holter monitor testing and possibly an echocardiogram. Dogs that do not show signs of ARVC and have positive attributes could be bred to dogs that are negative for the mutation. Puppies should be screened over a few generations, and those that are negative for ARVC may be selected to replace the mutation-positive parent and gradually decrease the number of mutation-positive dogs from the population.

Boxers that are homozygous positive, or have two copies of the mutated gene, should not be bred unless they are of an exceptional quality and it is important to maintain their positive attributes. These dogs have more severe disease and will certainly pass the mutation on to their offspring. They should only be bred to a negative dog. After two generations of negative crosses, a negative puppy could be selected as a replacement.