Bringing a new puppy into the family is an exciting time and should be a time of great joy. It can be particularly distressing to find that your new arrival has a problem. It is important that you get your new puppy checked over by your vet so that any obvious problems can be identified before you become too attached to it.
Congenital defects are caused by abnormal development of the foetus and disease is present from the time that the animal is born. However, although the disease is present from birth, signs may not be noticed until later in life. Congenital defects can occur in any part of the body and the heart is no exception. The heart is a complicated structure and as it develops there are many things that can go wrong.
Around 1 in 200 dogs have a congenital heart problem. No-one knows why the heart develops abnormally in some animals. It is probably usually the result of a combination of environmental conditions and genetic factors. Some diseases are more common in particular breeds and so it is likely that they are partly passed from parents to offspring. For this reason animals with congenital diseases should not be allowed to breed.
If defects are severe then signs can be marked, but in some cases you may not even know that there is anything wrong with your pet. Often one of the first signs of a heart defect is a heart murmur detected by a vet during routine examination.
When you buy a new puppy you should take them to your vet so that your vet can check them over. Your vet should listen to their heart and will be able to tell if a murmur is present. However there are some diseases that cause no signs in the early stages.
If heart disease progresses then an animal with a congenital condition can go on to develop heart failure. This may occur relatively quickly within the first few weeks or months of life if the defect is serious. However in many cases no signs are shown until the animal reaches adulthood.
There are a number of congenital heart diseases and some of these more commonly affect some breeds of dogs than others. The diseases are caused by abnormal development of the blood vessels (abnormal connections or narrowing), the valves or as a result of abnormal connection between different parts of the heart (hole in the heart).
The most common forms of congenital heart defect include PDA (patent ductus arteriosus) where there is a communication between blood supply into and out of the heart; narrowing of the large blood vessels taking blood away from the heart – to the lungs (pulmonic stenosis) or to the body (aortic stenosis). Sometimes there is abnormal development of the valves between the various chambers of the heart usually affecting the mitral valve (mitral dysplasia). It is rare for dogs to have a ‘hole on the heart’.
If your vet detects a heart murmur on examination they will need to do further tests in order to find out what is causing the problem. X-rays might help but ultrasound will be needed to find out exactly what is wrong with the heart. Your vet may need to refer your pet to a vet who specialises in heart disease for detailed examination. This will allow the best treatment plan to be formulated.
Unfortunately the long-term outlook for animals with severe congenital heart disease is usually not good. The only cure for heart defects is surgical correction. Some defects can be corrected by an operation, for example to tie off an abnormal blood vessel – for other defects there is no specific treatment.
In cases of pulmonic stenosis it may be possible to reduce the narrowed valve by stretching it using a special catheter (balloon valvuloplasty). In some cases animals have no problems with their disease and can live with the condition.
If animals develop heart failure then this can be managed with drugs to control signs.
If your pet can have surgery to correct their heart defect they will probably need to be sent to a specialist surgeon. However recovery from the operation is usually rapid and they may be back to normal in a week or two.
Unfortunately if there is no surgical option for your pet then they may need drug treatment for the rest of their life. It can be very distressing to watch a young animal suffer with heart disease and, if there is no treatment for your pet, you should discuss with your vet whether euthanasia might be the kindest option.