Discovering Irregular Heart Sounds
Like people, dogs can have heart problems. In fact, heart disease is one of the most commonly diagnosed problems in dogs, especially in older canines.
Some canine heart diseases are congenital, or present at birth. These may or may not be genetically passed through from one or more generations. Other heart irregularities are acquired and develop gradually over time.
A dog's heart is 0.6 to 0.9 percent of total body weight. Located in the chest cavity, the base of the heart is closer to the spinal column and the highest point is closer to the breastbone between the dog's front legs. This muscular pump is divided into four chambers, two on the left and two on the right.
Dogs suffer from heart problems such as heart base tumors, cardiomyopathy, heart murmurs, and irregular heart rhythms. There are two common types of heart disease that develop gradually over time and result in heart failure.
Dilated cardiomyopathy occurs mostly in large and giant breeds and causes the stretching of the heart muscle, producing swelling. The heart muscle becomes so weak that it cannot pump blood around the body.
Valvular heart disease can occur in any breed. As a dog ages the heart valves begin to wear out and degenerate. They cannot close properly and this allows blood to flow back and forth through the heart chambers. This reduces the blood supply to the body.
The Circulatory System
The heart, blood, and blood vessels — which include the arteries, arterioles, capillaries, and veins — comprise the circulatory system. It supplies all of the dog's tissues and vital organs with the oxygen and nutrients he needs for survival. The canine heart is very much like the human heart. Both have four chambers that include a right and left atrium and a right and left ventricle. The chambers on the right side receive blood from the body and send it to the lungs, where oxygen is added. The blood returns to the heart on the left side, where the left ventricle pumps the blood to the body.
Dogs have blood vessels just like people do. These include large arteries that connect to the abdomen, head, and heart, as well as smaller capillaries connecting to the arteries and veins. The arteries are large muscular blood vessels that carry oxygen and nutrients from the heart to the entire body. The system of blood cells is also the same in dogs as it is in humans. Red blood cells carry oxygen, while white blood cells fight off infection. Platelets and plasma assist in blood clotting. The blood carries hormones, nutrients, and waste products to and from the cells.
Von Willebrand's disease (VWD) is a common inherited bleeding disorder. It is a blood clotting defect that is prevalent in more than fifty breeds. Dobermans are the most frequently affected, but it is also found in Corgis, Doberman Pinschers, German Shepherds, German Shorthaired Pointers, Golden Retrievers, Miniature Schnauzers, Shetland Sheepdogs, and Standard Poodles, among others. A test checks for the clotting factor in the blood.
During a routine checkup, your veterinarian will examine your dog's heart by listening to the heart and lungs. She will observe the quality of the dog's pulse, check the color and nature of the mucous membranes, and look at the blood vessels in the eyes. The doctor will use her hands to feel for abnormalities in the abdomen and chest to determine if the heart is beating harder than normal. She can tell if there is pain and whether the organs are enlarged or if there's a mass or fluid inside. If she suspects an abnormality, chest X-rays will reveal the size and shape of the heart, the condition of the lungs, and the blood vessels. The electrocardiogram (ECG) assists in evaluating the rate and regularity of the heartbeat, while a blood sample checks the hydration status and functioning of other organs for signs of other underlying diseases.
Sometimes puppies are born with circulatory system problems. The chambers of the heart may not be fully formed or may be malformed. Blood vessels may have holes, may be too small, or may be situated in the wrong place. Heart valves may be defective and may not close properly. As puppies grow, they may develop infections, heart failure, or genetic predispositions to heart ailments.
Signs of Problems
During the early stages of heart disease there are few signs that most breeders could easily recognize. Many precursors to heart failure can be diagnosed only by a veterinarian's examination.
Heart problems are often discovered when a dog needs to have surgery or a dental cleaning. Veterinarians usually perform laboratory blood work and an electrocardiogram to screen for any problems before the procedure. An ECG will help rule out cardiac blockages, arrhythmia (irregular heart beats), and cardiac enlargement.
Heart disease and heart failure are different. Heart failure is caused by heart disease, although many types of heart disease don't result in heart failure. Symptoms of heart failure include the accumulation of fluid in the lungs, chest cavity, or abdomen; and low peripheral perfusion, or blood flow to the extremities. The signs of mild to moderate heart failure may include heart enlargement, coughing or hacking, wheezing, swelling in limbs, abdominal bloat, and poor circulation. Also be aware of decreasing energy or stamina, especially after exercise or exertion.
Severe heart disease symptoms include difficulty breathing, fainting, inability to exercise, loss of appetite, and weight loss. Sometimes owners do not recognize the early signs of heart failure until it is too late. One cause of potential heart failure is heartworm disease. Before dispensing heartworm preventative, the veterinarian will take a blood panel to test for the presence of heartworms. Heartworm disease is frequently detected through the blood test long before routine symptoms of the disease become apparent.
Diagnosing Heart Disease
Heart disease is frequently diagnosed in both small and large breed dogs. Genetics play a role in whether a dog will develop heart disease, but there are other risk factors as well. If a dog has a condition that increases the demand for cardiac output, such as anemia or pregnancy, there is an increased risk of heart disease. Dogs that are not given heartworm preventatives are at a higher risk for contracting heartworms, a devastating but avoidable condition.
Heart failure is a major canine health problem. According to the American Veterinary Medical Association, approximately 3.2 million dogs in the United States acquire some form of heart disease and may be in heart failure. Heart disease can be present at birth or acquired later.
All conditions need to be diagnosed by a veterinarian, and may involve laboratory tests. If heart disease is suspected, the veterinarian will want to rule out heartworm disease with a heartworm test, chemistry blood panel, and X-rays. X-rays will also help determine the presence of any tumors, lung congestion, or fluid surrounding the heart.
Once a thorough medical assessment has been made, a natural approach can help prevent a minor problem from progressing. At the very least, natural remedies may help slow the disease. Natural approaches are available to complement conventional medications.
