What Is Valve Disease?

Atrioventricular Valvular Insufficiency (AVVI) or mitral valve disease is the most common form of heart disease in the dog. Three quarters (75%) of the cases of canine heart disease in North America are caused by chronic valve disease.¹

As the name suggests, this disease affects one or more of the heart valves. Heart valves normally form a perfect seal when closed. However, in valve disease one or more of these valves "leak," allowing blood to be pumped backwards. This backward flow creates a noise, called a murmur, which your vet can hear with a stethoscope. Listen to a heart murmur.

Valvular disease is 1.5 times more common in male dogs than females.¹ This form of heart disease usually occurs in small- to medium-size dogs, less than 44 pounds (20 kg).^1,2 The most susceptible breeds are Cavalier King Charles Spaniels, Poodles, Schnauzers, Chihuahuas, and Fox Terriers.⁵