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Congestive Heart Failure In Dogs
The heart is one of the most miraculous machines ever devised. It is capable of operating non-stop for many decades. The heart is a pump that is responsible for moving blood through the network of blood vessels found in the body. It is actually two pumps, one on the right side, one on the left. The right side of the heart is a smaller, lower pressure pump that receives blood from the body and delivers it to the lungs where the blood gives up carbon dioxide and is replenished with oxygen. The left side of the heart is a larger, more muscular pump and operates at a much higher pressure. It receives the oxygenated blood from the lungs and delivers it back to the body. This cycle continues non-stop during life.
What is CHF?
Congestive Heart Failure is the inability of the heart to provide adequate circulation to meet the body’s needs. It is the end result of weakened heart muscle. When the output of blood from the heart is decreased, the relative amount of blood entering the heart is increased. This increase in blood upstream from the heart changes the balance of fluid pressure in the upstream blood vessels and surrounding tissue. When these pressures are increased, blood fluid leaves the vessels and congests the surrounding tissue.
Causes of CHF
Degenerative valvular disease is a condition that reduces the ability of heart valves to prevent the back flow of blood during ventricular contraction. In dogs, the valve found between the left atrium and left ventricle is most commonly involved. When this happens, it is called mitral valve disease.
In the early stages of congestive heart failure, the dog’s body is able to compensate for a lower output of blood from the heart. Blood vessels in the body constrict increasing the resistance to blood flow, the heart rate will be elevated, and a mechanism will be activated that causes the dog’s body to retain sodium and water. These three factors lead to an increase in blood pressure which helps to maintain normal blood circulation. But over time, the increase in blood pressure can lead to accumulation of fluid in tissues and body cavities. Decrease in output on the left side of the heart leads to fluid accumulation in the lungs called pulmonary edema. If this occurs on the right side, there will be congestion in the abdomen or other body spaces
- Exercise intolerance
- Decreased appetite
- Syncope (fainting)
- Difficulty sleeping (especially on its side)
- Ascites (fluid in the abdomen)
It is important to correct any underlying cause whenever possible. Treatment of congestive heart failure involves feeding the dog a low salt diet, restricting exercise, and giving appropriate medications to increase heart function and prevent cardiac arrhythmias.
Exercise is beneficial, but only for dogs that are not symptomatic. If symptoms such as easy tiring, coughing, or rapid breathing appear with exercises, do not allow your dog to engage in activities that elicit these symptoms.
Various drugs are available that increase the force and contraction of the heart muscle or decrease the workload. This includes the digitalis glycosides, calcium channel blockers and anti-arrhythmic. Dog with CHF may benefit from vitamin-B supplement and taurine or carnitine. With proper care and medication a dog with CHF can live a longer and more comfortable life.
Dr Sharad Singh Yadav is the Chairman of Advanced Pet Hospital & Research Centre which is open 24 hours throughout the year and located in Bishal Nagar, Kathmandu. He may be contacted on tel: 4422855 or email: firstname.lastname@example.org