Your dogs heart is very similar in structure and function to your own. The most common cause of heart disease in dogs affect either the valves or muscle of the heart. Understanding your dogs condition will help you help your dog.
There are two main causes of heart failure in dogs.
- Myxomatous mitral valve disease (MMVD)
- Dilated Cardiomyopathy
Myxomatous mitral valve disease
Myxomatous mitral valve disease (MMVD) also sometimes known as “Endocarditis” or “chronic valvular insufficenty”, this is the most common form of heart disease in dogs. It usually occurs in small to medium size dogs and some breeds are more susceptible than others. Breeds that are more commonly affected include: cavalier king Charles spaniel, poodle, schnauzer, Chihuahua, fox terrier and Boston terrier. It is mostly older dogs who suffer from this disease and male dogs more commonly than affected than female.
MMVD is a disease affecting the surface of the heart valves. The valves normally form a perfect seal between the chambers of the heart, ensuring that when the heart contracts blood flows in the correct direction. MMVD causes the edges of the valve to become thickened, lumpy and distorted. This means that the seal is “leaky” when the heart pumps blood. Some of the blood flows the wrong way back to the previous chamber of the heart. The backwards flow creates turbulence which results in a murmur that can usually be detected by a stethoscope.
Once the valves are leaky, circulation becomes impaired initially your dog’s body may make adjustments to allow it to cope and often dogs which have a heart murmur are affected for many years. However eventually they will become unwell and begin to show clinical signs of heart failure. Regular visits to your vet are important for early detection of heart disease and to monitor the treatment of a dog with heart disease.
Dilated Cardiomyopathy (DCM) is a disease of the heart muscle, rather than the valves. DCM is the most common in the medium to large breeds of dogs with young to middle age dogs most frequently affected. Although the exact underlying cause of DCM is not clear, certain breeds tend to be predisposed to the disease suggesting a genetic component.
In DCM the heart muscle becomes weak and flabby, so the heart fails to pump effectively. Circulation is greatly reduced as a result, with blood supply to the organs reduced. In addition the heart stretches and enlarges. Usually dogs with DCM tend to develop clinical signs more quickly than those with MMVD.
Treating heart failure in dogs
Although your dog may have been diagnosed with a heart problem such as MMVD or DCM there are still many things that you can do to help your dog live a longer more comfortable life.
As well as medications recommended by your vet, life style changes may also have a role. It may be necessary to change your dog’s exercise regime, in some cases this may mean complete rest, in others a controlled exercise regime is recommended. It is important to remember that there is no cure for either of these causes of congestive heart failure. However, there are treatments that not only greatly improve your dog’s quality of life but it can also significantly extend your dog’s life span compared to being left untreated.