Cavalier King Charles Spaniels or cavs as they are commonly called are a royal breed that originated in the United Kingdom. This toy breed comes in four different colors-blenheim, tricolor, black and tan and ruby. Most cavs possess a wonderful personality, making them an outstanding family dog. Veterinarians enjoy working with this breed because of their temperament.
Unfortunately, some of these spaniels suffer from a serious cardiac problem involving a heart valve. Name the valve? What happens when this valve fails?
Diagnosis: Mitral Valve
The mitral valve is located on the left side of the heart between the ventricle and atrium. When the valve is open, blood flows from the atrium into the ventricle. Once the ventricle is full, the valve closes and the ventricle contracts pumping blood out the aorta to the body. Cavalier King Charles Spaniels suffer from a condition called early onset mitral valve disease. The mitral valve does not close properly allowing blood to flow backwards. The condition worsens over time until heart failure occurs. Mitral valve disease is a problem in other toy breeds as well. What is unique about cavs is the early age of onset, often less than five years of age.
Clinically, the first sign of early onset mitral disease is a heart murmur caused by the blood flowing backwards into the atrium. When a murmur is heard, the next step is a cardiac ultrasound to assess severity. Because the problem is so common in cavs, I recommend all breeding animals undergo a thorough evaluation by a veterinary cardiologist prior to breeding. Of course, all cavs should have regular check-ups that include a thorough auscultation of their hearts.