In addition to acquired common heart diseases, there are also common congenital heart diseases. At first glance, congenital heart disease sounds very scared and difficult to manage. In contrast to acquired heart diseases (most are degenerative disease and could not be cured), some congenital heart diseases can be cured if it is early diagnosed. After successful treatment, the expectancy and quality of pets’ life will be as same as normal animals.
Patent Ductus Arteriosus (PDA) is one of the more common congenital heart defects in dogs. Every normal fetus has a ductus arteriosus. This enables the umbilical circulation to supply oxygen, allowing blood bypass the fetus’ non-functional lungs. The ductus arteriosus is a small channel that connects the aorta and the pulmonary artery. At birth, this system is no longer needed as dogs can breath and lungs work, allowing blood easier to flow to the lungs rather than through the ductus. The ductus closes within the first 3-10 days of life. If the ductus does not close it or “patent”, the blood from aorta will flow to the pulmonary artery not the body as it is supposed to. The increased circulation will cause more workload of the heart and finally will result in congestive heart failure.
A PDA has a characteristic murmur can be heard by a veterinarian during your pet’s first check-up. And an echocardiogram can evaluate the heart function and the chamber size, also can visualize the ductus. PDA is a treatable congenital heart disease and can be cured once early diagnosed (before congestive heart failure, usually before 1 year old). There are many ways to occlude the patent ductus, including traditional ligation of the ductus by opening chest, or interventional occlusion of the ductus by a coil or a special device.
Finally, we would like to introduce pulmonary hypertension (PHT) in the rest of this topic. PHT means the blood pressure of lungs is over normal range. Unlike systemic hypertension, it is only indicated elevated blood pressure of lungs. The reason of PHT can be increased pulmonary artery pressure (like heartworms infestation), or parenchymal lung disease caused by chronic respiratory disease (like collapsing trachea, asthma, lung consolidation...etc). PHT could be developed due to MMVD.
Moderate to severe PHT with diffused parenchymal lung disease will also result in pulmonary edema and then breathing difficulty. As mention previously, heart disease will cause pulmonary edema, too. In addition, dogs with MMVD are usually the breeds which are predisposed to the airway disease also. X-ray and echocardiogram can help it to differentiate pulmonary edema is from heart disease or airway disease. Oxygen and Viagra are the useful tools to treat PHT.
If your pets are in an emergency or if you have general inquiries, please do not hesitate to contact Veterinary Emergency Centre.
General Hotline: 2334-2334
24-Hour Emergency Hotline: 6828-6620
