About puppy heart murmurs

• Heart murmurs have been found to be common among Boxers.
• It should be emphasised that these do not affect health in the great majority (95%) of dogs.
• The few dogs with very loud murmurs, however, may be subject to fainting, and there may even be sudden death.
• Aortic stenosis is the heart condition most commonly associated with these heart murmurs, but cases of pulmonic stenosis and cardiomyopathy, as found in other breeds, have also been detected.
• Typically, clinical signs of aortic stenosis first appear in the young adult although, rarely, puppies can be affected.
• It should be stressed that minor "flow" murmurs are commonly found in young Boxer puppies, as in other breeds, but most disappear by about 16 weeks of age. Even if they persist there may be no cause for alarm if they are quiet. Such genuine "flow" murmurs are not associated with heart disease in the adult.
• The incidence of Boxers with severe aortic stenonsis has increased in recent years, although the numbers of cases are still very low in relation to the numbers of dogs bred.
• To rectify the situation the Boxer Breed Council has, with the aid of veterinary cardiologists throughout the country, developed a system of testing based on simple stethescopic examination by the cardiologists. A breeding control scheme has also been established.
• Therefore, should a heart murmur, or any heart condition other than a genuine puppy "flow" murmur, be recognized in a Boxer it should be referred through the vet in charge to one of the cardiologists. The breeder and the Breed Council geneticist should be informed of the result.
• Dependent upon the findings the condition may be treatable.
• If a puppy "flow" murmur is loud and persists, the vet in charge may recommend that further advice be sought from a specialist cardiologist.