The Cardiac Education Group is a group of board-certified veterinary cardiologists from both academia and private practice that offers independent recommendations for the evaluation and treatment of canine heart disease. The group is committed to providing resources and information on the diagnosis, treatment and management of heart disease and heart failure in dogs and cats in order to promote early detection and diagnosis with greater accuracy and confidence.
The CEG mission is to offer educational recommendations and resources that will help veterinarians diagnose, treat and manage heart disease and heart failure in dogs and cats, improving the lives of pets with heart disease.
John D. Bonagura, DVM, MS, Diplomate ACVIM
Professor, Veterinary Clinical Sciences, Ohio State University
Barret Bulmer, DVM, Diplomate ACVIM
TUFTS Veterinary Emergency Treatment & Specialteis, Walpole, MA
Whit Church, DVM, Diplomate ACVIM
Arizona Veterinary Specialists, Gilbert, AZ
Sonya Gordon, DVM, DVSc, Diplomate ACVIM
Associate Professor of Cardiology, Texas A&M University
Brian Scansen, DVM, Diplomate ACVIM
Assistant Professor of Cardiology, Service Head, Cardiology & Cardiac Surgery, Colorado State University
Alan Spier, DVM, PhD, Diplomate ACVIM
Florida Veterinary Specialists, Tampa, FL
Rebecca Stepien, DVM, MS, Diplomate ACVIM
Clinical Professor, School of Veterinary Medicine,
University of Wisconsin-Madison
As the name suggests MMVD affects the mitral valve which is located on the left side of the heart between the atrium and the ventricle. MMVD is a slowly progressive condition in which the mitral valve thickens. Normally, heart valves form a perfect seal when closed ensuring that blood flows in the right direction through the heart. Therefore the function of the mitral valve is to channel blood from the left atrium into the left ventricle. However, in MMVD the thickening of the mitral valve results in an imperfect seal and allows blood to “leak” backward into the atrium as the ventricle contracts.
MMVD affects about:
This form of heart disease usually occurs in small to medium size dogs. The most susceptible breeds are Cavalier King Charles Spaniels, Poodles, Schnauzers, Chihuahuas, and Fox Terriers. Also, male dogs are more commonly affected than females.
Eventually all forms of heart disease will likely result in CHF. As heart disease progresses the heart weakens and blood continues to leak backward into the atrium. This overloads the atrium and causes fluid to leak out of the blood vessels into the lungs (known as pulmonary edema). In addition, blood flow out of the heart slows reducing blood flow to the key organs. At this stage, the signs of CHF become evident.
The most common signs of CHF include:
Some or all of the clinical signs above may appear, and all have an impact on the dog’s quality of life.
The diagnosis of CHF due to MMVD is usually preceded by the detection of a heart murmur during routine veterinary check-ups using a stethoscope. A heart murmur is the sound caused by blood leaking backward into the atrium from the ventricle. To diagnose CHF the veterinarian will need to complete a thorough clinical history and physical examination. They may also recommend some of the following tests:
Treatment of CHF due to MMVD begins when the dog shows clear clinical signs of heart failure, and is tailored for the individual pet. Since surgery to prevent further deterioration is rarely possible in canine patients, management of heart failure seeks to improve quality of life and extend life expectancy through daily medication.
Hypertrophic cardiomyopathy (HCM) is most common in cats. HCM causes the heart’s muscle to thicken, making it difficult for the heart to pump blood through the body. Thickening of the heart muscle can also be a natural response to other diseases, such as hyperthyroidism, kidney disease and hypertension.
[i] Sisson D. Valvular heart disease in dogs. Abstract at WSAVA 2002.
[ii] Ware WA. Cardiovascular disease in small animal medicine. Ames, IA: Blackwell Publishing.