Two distinct areas of heart problems in dogs involve either 1. the heart muscle (myocardium) or 2. the valves in the heart. (dogs tend to have more valvular problems and cats tend to have more problems with the heart muscle).
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Heart problems can be genetic (inherited), congenital or acquired (develop as the dog grows older). |
Let’s try to break this down into more understandable areas. |
Congenital heart problems in dogs include malformation of the heart or great vessels and account for 60% to 70% of the diagnosed heart problems. Some of the congenital heart problems are: |
Patent Ductus Arteriosus which is a continuous heart murmur with maximal intensity over the left craniodorsal cardiac base. |
Ventral Septal Defect is a systolic murmur with maximal intensity over the right ventral precorium: less often maximal intensity is over the pulmonic valve area and pulmonary artery. |
Atrial Septal Defect is a systolic murmur with maximal intensity over the pulmonic valve area and pulmonary artery. In this case, the second heart sound may be widely split. |
Pulmonic Stenosis is a systolic murmur with maximal intensity over the pulmonic valve area and pulmonary artery. |
Valvular and subvalvular aortic stenosis is a systolic murmur with maximal intensity over the subaortic or aortic valve area and radiating into the ascending aorta. The murmur may also be prominent over the right cranial thorax. |
Mitral Valve Dysplasia is a systolic murmur with maximal intensity over the left apex and mitrial area. |
Tricuspid Valve Dysplasia is a systolic murmur with maximal intensity over the tircuspid valve area. |
Right-to-left cardiac shunt – Variable – a systolic murmur at the left base is often detected: cyanosis is an important clinical sign. http://devinefarm.net/health/ofaheart.htm |
Please note the disorders listed above involve the valves in the heart. They are characterized by a heart murmur. It is very important to always have a puppyês heart checked by a veterinarian, and for a more definitive diagnosis have a cardiologist board certified veterinarian do the check up if there is any question. If a murmur is found, it will be placed into one of these classifications: |
Grade 1: A very soft murmur only detected after very careful auscultation. |
Grade 2: A soft murmur that is readily evident. |
Grade 3: A moderately intense murmur not associated with a palpable precordial thrill (vibration). |
Grade 4: A loud murmur; a palpable precordial thrill is not present or is intermittent. |
Grade 5: A loud cardiac murmur associated with a palable precordial thrill; the murmur is not audible through the thoracic wall. |
Grade 6: A loud cardiac murmur associated with a palpable precordial thrill and audible even through the thoracic wall. http://devinefarm.net/health/ofaheart.htm |
Signs of valvular problems include lack of tolerance for exercise, coughing (especially first thing in the morning or night), and fainting and weight loss. www.v-e-t-s.co.uk/heart_disease%20dog.htm |
There are murmurs known as •innocentê murmurs. These murmurs can be detected in puppies when they are examined by a cardiologist. An •innocentê murmur will resolve itself by age four months or so. If a murmur remains past that age, it would be wise to visit a veterinarian cardiologist for a proper diagnosis. |
The other common type of heart disorder is cardiomyopathy. This is described as having a thin heart muscle. This can be caused by infection, autoimmune disorders that affect the heart or a nutritional deficiency. It generally affects large to giant breed dogs, young to middle aged. Symptoms include increased thirst, increased appetite, loss of weight, fluid accumulation in the abdomen and digestive problems. If these problems are seen, please check for both hypothyroid conditions and the heart as these symptoms are common for both disorders. www.v-e-t-s.co.uk/heart_disease%20dog.htm |
A reverse problem of the above is hypertrophic cardiomyopathy (HCM) which is a thickening of the muscle walls of the heart. This is more common in cats, but can also be seen occasionally in dogs. http://animalpetdoctor.homestead.com/Heart.html |
The last common heart problem in dogs is caused by old age. It is where the arteries in the heart start stiffening which causes a lack of blood flow to the heart. Poor diets, leading to anemia in older dogs, can also cause a lack of oxygen to the heart. |
If a dog is suspected of having one of these disorders, veterinarians can employ various methods to determine if the heart is affected. These include: |
– Listening to the heart for murmurs, congestion or irregular heart beat. |
– Radiographs of the chest to look for congestion and to see if the heart is abnormally large. |
– Electrocardiogram (ECG) can detect irregular heartbeats |
– Echocardiogram detects through sound waves to locate any defects in the heart. |
– Complete blood and urine panel |
These tests should also include testing for other problems of the heart, including heartworms, tumors, bacteria infections, thyroid panel and autoimmune diseases that can affect the heart function. |
Traditional Treatment for Heart Disease
Several prescription medications are used to help heart function. These include: |
Diuretics: These help in the presence of fluid build up around the heart or abdomen. This would include furosemide and spironolactone. Antihypertensive drugs (vascodilators) assist in dilating arteries and veins. This helps the heart to pump blood more efficiently. These include enalapril, capoten, enacard and nitroglycerine. |
Digitalis glycosides: Help to increase the force of the hearts contractions. Must be carefully monitored as the side effects can be toxic. Includes Foxaline, digitoxin and lanoxin. Beta Blockers- These are helpful in hypertrophic cardiomyopathy and dilated cardiomyopathy to slow the heart rate which helps the ventricles fill with blood between contractions. This includes atenolol and propanolol. www.mesavet.com/library/heartmeds.htm |
http://www.vetheart.com/diseases.html. Most veterinarians will recommend a low sodium diet, and a prescription dog food. |
Alternative Therapies in Nutrition and Supplements
Taurine
New studies in nutrition and the heart in canines have shown some interesting results. Taurine has been shown to be essential to cats, but the emphasis for dogs has been neglected. New studies show that certain breeds prone to dilated cardiomyopathy (DCM), such as Newfoundlands, have a tendency to have taurine deficiencies. Studies are also currently being performed on Doberman Pinschers in this area. While scientists believed that dog foods high enough in sulfur and proteins would allow canines to produce taurine, they now believe this may not be true. It is thought taurine metabolism may well contribute to DCM. www.vetmed.ucdavis.edu/CCAH/Update06-2/6-2_Taurine.html |
It is also thought that current levels of taurine found in commercial diets may not be adequate to meet the needs of canines. http://nss.vet.ohio-state.edu/DDT/new%20pages/nut&card.htm |
Taurine is abundant in fresh meat sources, but it is felt that processing animal proteins at high temperatures may affect the integrity of this amino acid. While taurine may be added to the diet as a supplement, it can also be found in raw or lightly cooked meats, such as chicken, beef and organ meat. While a raw diet might be the best diet for a dog with a compromised heart ® one low in sodium and high in taurine, if changing to a total raw diet seems daunting, then adding some fresh meat to the commercial diet would certainly be helpful. |
L-Carnitine
Current studies have shown heart diseases in dogs demonstrate a low incidence of l-carnitine in their systems. L-carnitine is an amino acid that helps maintain the integrity of long chain fatty acids in the cells of the heart muscle. When l-carnitine is lacking in the diet, the heart muscle will suffer. L-carnitine, like taurine, is found in animal protein. L-carnitine is highest in beef and pork sources. Plant sources are very poor for both of these amino acids. www.gooddogmagazine.com/heartfailure.htm |
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