Congenital heart diseases are not uncommon in puppies and some of these are inherited. Pedigree dogs have many inherited diseases and different breeds each have their own problems. Many dog breed societies employ testing schemes to detect individuals affected with certain conditions at any early stage of the disease at an early age. Early detection is important, not only to ensure appropriate treatment for affected dogs but also so that these animals can be excluded from breeding programmes to prevent them passing on the disease to their offspring.
What heart testing schemes are available?
There are a number of breed testing schemes which allow early detection of these conditions. The following breed clubs operate heart testing schemes:
Boxer: aortic stenosis
Bull terrier: aortic stenosis and mitral dysplasia
Cavalier King Charles spaniel: mitral valve disease
Great Dane: dilated cardiomyopathy (DCM)
Irish Wolfhound: dilated cardiomyopathy (DCM)
Newfoundlands: aortic stenosis
Pyrenean sheepdog: patent ductus arteriosus (PDA)
Field Spaniel: prevalence of murmur and arrhythmia
How do I get my dog tested?
Heart testing for the breed schemes can only be carried out by certain specialist veterinary cardiologists. A list of all currently eligible vets (and their contact details) can be found on the Veterinary Cardiovascular Society website: http://www.bsava.org.uk/vcs/.
An appointment can be made with a specialist veterinary surgeon in your area at their practice or, in some cases, the specialist may come to your vet’s practice. Additionally many of the breed clubs arrange for specialists to be available at certain major dog shows – you should contact the individual breed societies for information on this.
Why do the breed clubs run these schemes?
There are a number of advantages to the breed club of running these schemes:
The clubs can identify unaffected (or less severely affected) animals which can then be used for breeding.
The number of affected dogs in the breed can be calculated so that clubs can monitor whether the disease is becoming more or less common and whether the breeding programmes are working.
To identify affected animals so that owners and vets caring for these animals can be advised on treatment.
What tests are included in the screening?
The exact format of the investigation will depend on the individual breed scheme. The three standard tests used for investigation of heart disease are:
Listening to the heart with a stethoscope (auscultation) Using a stethoscope the vet can identify any heart murmurs and abnormal heart rhythms which may indicate a structural defect in the heart. In many cases detection of an abnormality with a stethoscope will indicate that further investigation is required.
Performing an ECG An ECG allows monitoring of the heart rhythm and rate. Some breeds of dog, notably boxers and dobermanns, develop heart conditions that specifically affect their heart rhythm. Sometimes your vet will be able to perform an ECG in the surgery but for many conditions it is necessary to fix a mobile device to the dog which is worn for 24 hours or longer the device is then removed and the information sent away for analysis.
Ultrasound of the heart Specialist veterinary cardiologists can use ultrasound to examine the heart in detail. This can be done in most dogs without any form of sedation or anaesthesia and in some breeds it can be done without clipping the hair. With ultrasound the vet can examine the chambers and valves of the heart to detect any abnormalities in heart development or function.