You will read and hear much about heart testing Boxers, the heart testing scheme has been in use for about thirteen years now, we have always tested our breeding stock and adhered to breed council guidelines. However there can be confusion regarding the testing of Boxers so, to clarify things a little:

The current heart scoring system DOES NOT make allowances for half marks in heart scoring. You will not see a dog or bitch graded on the heart list as a 1.5, or 0.5, they are either 0,1,2,etc. For example, if there is a shred of doubt when scoring a dog, then a one MUST be graded as a two, unless the animal is dopplered (a type of ultra sound scan carried out by a veterinary cardiologist) in this instance a more accurate figure can be given.

Simplistically, the specific recommendations for breeding are:

All breeding stock should be screened by designated cardiologist. Those animals which are free of heart murmurs (grade 0) may be considered free of aortic and pulmonic stenosis, and are suitable for breeding purposes.
Those animals which have a minor murmur (grade 1) may be accepted as normal and are suitable for breeding purposes.

Bitches who are scored over a 1, therefore as a grade two, are considered acceptable as brood bitches providing they are mated to a clear dog, either a 0 or a 1.
Dogs with murmurs of a grade two or louder, should not be used as stud dogs, except in exceptional circumstances, then only to a clear bitch. One of the reasons for this is because a bitch is only able to have a limited number of puppies in her lifetime, where a dog is potentially able to sire thousands of puppies. Therefore this is self-limiting.
Genetics is not an exact science (if only it were that simple), we all know of a 0 being mated to a 0, yet some of the pups may be graded as 2’s, but, the heart testing scheme is beginning to reduce the problems of heart disease among our dogs, and by following breed guidelines we as breeders are now beginning to see the rewards of heart testing our breeding stock before they are bred from.

Ref: Boxer Breed Council.


Click here to go to the Boxer Breed council page for more information on general health issues, health screening and a list of cardiologists etc.

Here follows a copy of one of the typical information sheets we give to new owners, The handout sheet on Boxer heart murmurs for new puppy owners, - this sheet is recommended by The Breed Council that breeders hand it out.

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 breed, may also be detected.

Typically, clinical signs of aortic stenosis first appear in the young adult, but on rare occasions 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 sixteen weeks of age. Even if they persist, there may be no cause for alarm if they are quiet. Such "flow" murmurs are both associated with heart disease in the adult.

The incidence of Boxers with severe aortic stenosis has increased in recent years, although the numbers of cases are still very low in relation to the number 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 stereoscopic 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 recognised in a Boxer, it should be referred through the vet in charge to one of the cardiologists. The breeder and breed council geneticist should be informed of their result.

Dependant on the findings the condition may be treatable.
If the puppy "flow" murmur is loud and persists the vet in charge may recommend that further advice be sought from a specialist cardiologist.

The aims of the Boxer heart testing scheme is to try and ascertain the prevalence of heart murmurs, abnormal heart rhythms and other specific heart conditions.
It is also to confirm the cause of heart murmurs or abnormal rhythms by further investigations of any affected dogs.
To collate data for investigation of a possible genetic basis to any specific heart problems in the breed.
To advise the owner, breeder, and dog's veterinary surgeon when an abnormality has been found, and to advise and recommend any further investigations that may be required.

Auscultation - examining with a stethoscope

This is an essential part of examining the animals heart and circulation. Any heart murmurs are identified, timed, localised and graded ( 0-6 no half measures!) A careful note of the heart rhythm is also made.

Heart murmurs are a feature of most congenital heart defects (CHD) and mitral valve disease. Some common forms of congenital heart disease include aortic stenosis (AS), patent ductus arteriousus (PDA), and pulmonic stenosis (PS). Abnormal heart rhythms may occur without murmurs in dilated cardiomyopathy (DCM). Visit HERE to view an animated normal, healthy heart and HERE to view a unhealthy heart. View both links together to notice the differences

It may be difficult for a cardiologist to detect a quiet murmur in a noisy room or in a dog which fidgets. Some murmurs can increase or alter at different heart rates like after exercise or excitement.

If a significant murmur is detected the cardiologist may advise the condition be further investigated. Although all veterinary surgeons will listen to your dogs heart, breed club schemes use veterinary cardiologists, vets who have received training, and have passed post-graduate exams and is able to grade heart murmurs in a way which is consistent with other cardiologists.

This is always indicated when or if an abnormal heart rhythm is detected. It is most often used to screen for DCM (dilated cardiomyopathy) though it is less sensitive at detecting CDH or MVD.

Two dimensional echocardiography allows visualisation of a 'slice' through the heart in real time. It allows measurements to be taken and compared with normal values for the breed or size of the dog. Severe CHD, MVD, or DCM are usually evident using these techniques. However,Doppler is also required to confirm the diagnosis of the specific type of CHD, and to identify mildly affected animals. It will confirm whether or not there is a significant cause of the heart murmur, or whether it is innocent In some cases, it is difficult to be certain whether the dog has mild disease or an innocent murmur.

Doppler will allow the cardiologist to give a prognosis about the severity of any disease. Veterinary cardiologists normally carry our Doppler examinations, as this is a very skilled technique which requires considerable expertise and experience.