Heronbank Cavaliers

An item which came in on my Ask Anne Page prompted this article.

People’s hearts and pet hearts fail for different reasons. In humans, it is damage to the heart muscle itself (heart attacks) that usually begin the process of CHF. In pets, it is most commonly due to malfunctioning of the valves that direct blood flow through the heart but although people and dogs develop heart disease for different reasons, the mechanics of what is occurring in your pet’s heart is very similar to what occurs in the damaged human heart. All of the medications your veterinarian will use and all the techniques he will use to diagnose the problem are the same ones – used for the same reasons – in humans. So you can learn a lot by reading about heart disease in humans.

How Blood Flows ThroughYour Pet’s Body

ENLARGE THIS DIAGRAM

Animate the Circulation of Blood In Your Pet’s Heart

The circulatory system is a very complicated system with each part relying on a complicated interaction of chemicals and organs. The heart of all mammals is made up of four chambers. The upper left and right chambers are called the atria (atrium) and the lower left and right chambers are called the ventricles. Each of the four chambers has an inlet and an exit valve to prevent back-flow of blood. In smaller and medium breeds of dogs it is these valves – particularly the mitral valve that divides the left atrium from the left ventricle – that often fails first leading to an enlarged, inefficient heart. These four chambers to not fire one after another like a car motor. They all work together in rhythmic waves to keep the blood flow continuous.

The Electrical System Of Your Dog’s Heart

Animate the heart’s Electrical System

There has to be a bandmaster to coordinate the heart’s contractions. The signals for heart muscles to contract are electrical signals and the heart contains a system of wire-like nerves (perkinje fibers) to distribute that signal. When the electrical system fails, heart blocks, abnormal pulse rhythms, and uncontrolled quivering (fibrillation) of the heart, or portions of it, occur. These electrical signals are what are measured by an electrocardiograph.

The mitral valve is a good place for bacteria that enter the blood stream to become trapped – particularly if the valve is already misshapen. Pets with severe dental disease have mitral murmurs more frequently than those that don’t. Often these murmurs disappear in pets after a course of antibiotics. In some breeds, such as Cavalier KC Spaniels, increased susceptibility to valve disease can be an inherited genetic defect.

These events occur slowly and at different rates. Dogs with mildly to moderately enlarged hearts often show no signs at all. The first sign might be just a little reluctance on the part of your pet to play as actively as it once did. When an actual problem finally occurs, it is usually a dry cough accompanied by gagging. Excess fluid in the lungs is the cause of the unmistakable “cardiac cough”. These coughs tend to be worst when the dog is down and at rest.

Most pet owners find out their dog has a heart murmur during it’s yearly health checkup. A listen with a stethoscope should always be part of your pet’s yearly examination. When a murmur is detected, the vet needs to make some other observations and, perhaps, run some tests even though your pet appears completely healthy.

When heart failure is more advanced, owners tend to bring their pets in because of a group of problems that came on very gradually. The most common one is a dry cough. Most owners will say that this cough is worst when the dog is resting. These dogs are in still in early heart failure.

Dogs with more serious problems have all the symptoms of the prior groups. But they also have a distended pot belly. Their gums and tongue may turn purplish (cyanotic) when the dog exerts itself. Late in this intermediate stage the heart beat is often irregular and some beats may not be felt in its femoral pulse (pulse deficit). These dogs are in an advanced stage of heart failure. Although they may have enlarged tummies, their prominent ribs and spine show that their body has lost muscle mass.

Anything worse is a medical emergency. Heart failure progresses to fainting, profound weakness, a racing pulse and difficulty obtaining enough air.As heart function declines, the pet’s body is able to compensate for several weeks or months. However, at some point, its ability to compensate is no longer effective. At this point, dogs can go into severe heart failure in what appears to be a matter of hours.

No known medication will repair hearts. What they will do is allow your pet to live comfortably for a time.

Diuretics rid the chest and abdomen of excess fluid (water). They do this by encouraging the pet to urinate. They are very effective in stopping coughs and respiratory distress, when lung fluid buildup is the cause.

ACE inhibitors decrease the effort your pet’s heart must make to pump blood through its circulation by relaxing and expanding blood vessels throughout the body. Dogs in heart failure often have fragile kidneys as well so kidney function needs to be checked before these drugs are given and then monitored periodically.

We all want to do everything we can to keep our precious pets with us. Many pet food companies make low-sodium diets designed for pets with heart failure. They are sold only through veterinarians. If your pet will not eat them, there are some recipes for low sodium home-cooked diets on this website. Low sodium diets may be helpful in lessening fluid retention. But one must not restrict their pet’s salt intake too severely or too soon into the disease. Some have noticed improvement in their pets when they are given fish oil capsules containing Omega-3 fatty acids. Cold-water fish oil is a rich source of omega-3 fatty acids which seem to reduce inflammation throughout the body. Always use the gelatin capsule form and never straight fish oil. Purchase capsules marketed for humans that are known to be mercury-free.

There is absolutely nothing neglectful or cruel about accepting your local veterinarian’s diagnosis. You and your pet can enjoy each other’s companionship during the remaining time that your pet has. Good food and good loving time together are kind alternatives to more drugs, needles and more stress. Dogs do not fear or anticipate death as we do.

…  Anne