Heart Health in the Newfoundland

Quick answer

The Newfoundland is a breed that requires proactive heart health monitoring throughout its life. While not every dog will develop these issues, certain heart conditions are more common in this breed than in others. By keeping a close eye on your dog's breathing, energy levels, and gum color, you can catch early signs of distress and work with your vet to manage these conditions effectively.

Congestive Heart Failure

Congestive heart failure occurs when the heart is no longer able to pump blood efficiently to the rest of the body. In the Newfoundland, this is a recognised tendency. How this passes down is not settled, though there is evidence suggesting it may be linked to specific genetic factors. You might first notice your dog becoming unusually tired during walks, lagging behind, or showing a reluctance to exercise. At home, you may see your dog struggling to get comfortable or appearing restless at night. Your vet will listen to the heart for abnormal sounds and may suggest imaging, such as an ultrasound, to see how well the chambers are pumping. This condition is a recognised tendency in the breed.

Dilated Cardiomyopathy

Dilated cardiomyopathy is a condition where the heart muscle becomes thin and weak, making it difficult for the heart to contract properly. This is a recognised tendency in the breed. The way this is inherited is not fully understood, but it is a well-recognised issue for Newfoundlands. Owners often notice a decrease in stamina or a sudden onset of weakness. Because the heart cannot move blood effectively, fluid can build up in the lungs, leading to coughing or difficulty breathing. A vet will use an echocardiogram to measure the thickness of the heart walls and the strength of the contractions to confirm this diagnosis.

Subaortic Stenosis

Subaortic stenosis is a narrowing of the area just below the aortic valve, which forces the heart to work harder to push blood out to the body. This is a recognised tendency in the breed. It is inherited, and there are three grades of severity that a vet will look for during a physical exam. You might not notice anything at all in mild cases, but in more severe instances, your dog may faint or show signs of extreme fatigue. The vet will listen for a heart murmur, which is often the first clue. If a murmur is detected, an ultrasound is the standard test to determine the grade of the stenosis and the impact on the heart's function.

Myxomatous Mitral Valve Disease

This condition involves the degeneration of the mitral valve, which sits between the left atrium and the left ventricle. Over time, the valve fails to close tightly, allowing blood to leak backward. This is a recognised tendency in the breed, as Newfoundlands are large breed dogs with an increased incidence of atrioventricular valve disease. You might notice your dog developing a soft cough, especially after excitement or exercise. A vet will identify this during a routine check-up by hearing a specific type of heart murmur. An echocardiogram is the definitive test to see the valve structure and the extent of the leakage.

Ventricular Tachycardia

Ventricular tachycardia is an abnormal, rapid heart rhythm that originates in the lower chambers of the heart. This is a recognised tendency in the breed. It is often seen in dogs that already have underlying heart muscle issues, such as dilated cardiomyopathy. At home, you might notice your dog having sudden episodes of collapse, weakness, or unexplained lethargy. Because this condition involves the electrical system of the heart, a vet will use an electrocardiogram to map the heart's rhythm. This test is essential for identifying the irregular beats and determining the appropriate treatment to stabilize the rhythm.

Patent Ductus Arteriosus

This is a congenital defect where a blood vessel that should close shortly after birth remains open, causing abnormal blood flow between the heart's major arteries. This is a recognised tendency in the breed and is sometimes found alongside subaortic stenosis in Newfoundlands. You might notice a young dog struggling to keep up with littermates or showing signs of poor growth. A vet will often detect a continuous, machine-like murmur during a puppy examination. Early detection is vital, and an ultrasound is used to confirm the presence of the open vessel and assess the heart's workload.

Mitral Valve Dysplasia

Mitral valve dysplasia refers to an abnormal development of the mitral valve that is present from birth. This is a recognised tendency in the breed. It should be suspected in giant breed dogs that develop heart failure before one year of age. Owners may notice a puppy that is smaller than its peers, has poor exercise tolerance, or experiences rapid or labored breathing. A vet will listen for heart murmurs and use imaging to look at the valve anatomy. Because this condition can progress quickly, it is important to investigate any signs of heart failure in a young Newfoundland immediately.