Out of all the animals regularly examined by a veterinarian, slightly more than 10% exhibit some variety of cardiovascular disease. The cardiovascular system is quite unique compared to other organ systems. This is because any disease that attacks it usually doesn’t dissipate entirely, but becomes more severe with time, thus causing death. Furthermore, the heart is not visible and is well protected by the rib cage, therefore making it hard to diagnose and assess any cardiovascular diseases.
Heart disease can be described as any irregularity of the heart. This includes a wide array of conditions, such as congenital abnormalities and disorders that affect the physical built and proper working of the heart. Heart disease can be categorized using various methods and factors. These include whether the animal was born with the disease (congenital) or not (acquired), root factors (infectious or degenerative), the extent of the disease (long- term or short-term), medical status (right heart failure, left heart failure, or biventricular failure), or by deformation of thel structure (ventricular septal defect).
Heart failure is defined as any abnormality of the heart that leads to its failure to pump adequate quantities of blood to cater for the body’s requirements. Heart failure is not classified as a specific disease, but rather a condition which results from certain factors. These factors include congestion or an uncharacteristic build up of fluid, reduced flow of blood to the body organs, or unusually low blood pressure. These are all final consequences of some form of severe heart disease. However, it is important to note that the presence of heart disease doesn’t necessarily constitute conditions that will lead to heart failure. Heart failure, on the other hand, occurs if and only if the animal is suffering from heart disease which causes the above stated factors.
Diseases of the Cardiovascular System In Dogs
There are numerous abnormalities that affect the cardiovascular system, thus causing heart disease. These include:
- Valvular disease, where there is failure of the heart valves to shut or open as required.
- Myocardial disease, where the cardiac muscle is too weak to pump blood effectively or it relaxes improperly.
- Arrhythmia, due to the heart beating too slowly, too quickly, or too erratically.
- Vascular disease, where the blood vessels create immense interference that prevents proper flow of blood.
- Cardiac shunts. This is where there are openings between the chambers on the left side and right side of the heart.
- A situation where the quantity of blood is too low or too high, compared with the capability of the blood vessels to store that blood.
- Parasitic attack of the cardiovascular system, such as infection by heartworm disease.
The symptoms linked to any of these diseases are caused by insufficient blood flow through the organ, which is signified by intolerance to exercise, lack of energy, and loss of consciousness. Other symptoms associated to the diseases are due to blood damming up in organs, resulting in fluids leaking from blood vessels into tissues, signified by irregular build up of fluid in the lungs or abdomen. A dog is diagnosed as suffering from heart failure if it displays signs of having inadequate quantities of blood in the tissues to maintain ordinary heart function. A dog is diagnosed as suffering from congestive heart failure if it displays signs of blood accumulating up in poorly drained organs. When there is an extreme deficiency of oxygen in the blood, the mucous membranes tend to develop a blue tinge, in combination with an elevated concentration of red blood cells.
There are some diseases that outweigh others in terms of severity and number of cases diagnosed. Those diseases of utmost relevance in dogs, because of the number of cases in existence, are mitral regurgitation due to mitral valve dysplasia, dilated cardiomyopathy, arrhythmic cardiomyopathy in Boxers, and heartworm disease.