Cavalier Health

Cavalier King Charles Spaniels are wonderful little dogs that can live active, healthy lives for up to 14 years and beyond.  That being said, there are many breeders who are not doing the research and testing that is required to help improve the health of the breed.  Byers Peak will ALWAYS do the maximum testing on our breeding stock to ensure that you will receive the best possible chance of a healthy and carefree long life for your puppy.  Please read the information below carefully and feel free to ask questions about Cavalier health.

Mitral Valve Disease

Cavalier King Charles Spaniels are generally healthy, sturdy, small dogs. However, as with many other breeds, there are health concerns. The number one health concern is a form of degenerative valve disease called Mitral Valve Disease (MVD). Please take time to review this health summary.

Cavalier Clubs throughout the world are active in fighting diseases and disorders in this beloved breed by providing health clinics, funding breed specific research and delivering breed education programs. The findings from surveys performed by the late George A. Padgett, DVM, Veterinary Pathologist & Professor Emeritus at the College of Veterinary Medicine of Michigan State University and author of Control of Canine Genetic Diseases, indicate that mixed-breed dogs have more genetic diseases than purebred dogs. There are 215 known diseases in mixed-breed dogs, with 71 percent of them having defective genes. The idea that a mixed-breed dog is likely to have fewer genetic diseases than a purebred is a misconception. 

What is Mitral Valve Disease (MVD)?

The heart consists of 4 chambers, 2 atria and 2 ventricles, with the atrioventricular valves ensuring the blood flows from the atria to the ventricles when the heart is beating. A defect or weakness in the mitral valve, or left atrioventricular valve, allows some blood to move back into the left atrium. This is known as mitral regurgitation. This means the heart is less efficient at pumping blood through the body.

Mitral valve insufficiency is the most common of the acquired cardiac diseases in older dogs, affecting over 1/3 of dogs older than 10 years. However, in certain breeds including the Cavalier King Charles Spaniel, mitral valve insufficiency develops at a younger age, due to an inherited predisposition for the disorder.


The first signal that a dog might have Mitral Valve Disease is the development of a heart murmur. However, a dog with a heart murmur may live a full life span, depending up the progression of the disease in that particular dog. Some dogs that have developed heart murmurs at young ages have lived to the average lifespan of that breed. A veterinarian, while listening to a dog's heart, may hear a heart murmur on the left side. (Please note there are other causes for heart murmurs. To diagnose MVD, it will depend upon where the regurgitation is heard). The veterinarian will then grade the murmur for severity from Grade 1 (mild) to Grade 6 (severe) and depending upon the grade will advise proper treatment.

Severe Mitral Valve Disease will eventually lead to Congestive Heart Failure.

Implication for Owner

The Cavalier will have their heart checked during his or her annual visit to the veterinarian. Cavaliers that develop murmurs might have early signs of MVD. If the disease is present and progresses, the murmur will become more audible, the dog may become intolerant of exercise, respiratory rate will increase, fluid will begin to accumulate in the lungs and the dog will develop coughing and labored breathing.  In most cases, a Cavalier will not need heart medications until late in life.  There are treatments available to assist with management of advancing MVD. A board Certified Veterinary Cardiologist should be consulted to determine the exact mode of therapy for each Cavalier. 

Implication for breeders

At present, MVD inheritance in the Cavalier is speculated in the veterinary community, however, research funded by the ACKCSC Charitable Trust is ongoing to confirm this hypothesis.  The inheritance is suspected to be polygenetic (several genes involved) with multifactorial influences (e.g., dog's environment, food and weight). In other words, there would be a genetic predisposition for the disease but other factors will come into play similar to other species (such as humans).  The Cavalier King Charles Spaniel has been studied and screened for over 20 years thanks to the dedication and generosity of owners, breeders and cardiologists in the USA.  To date, other purebreds and mixed breed dogs predisposed to MVD have not been studied and screened to the level of Cavaliers.

The recommended health screenings for Cavaliers are annual auscultations (listening to the heart with a stethoscope) by board certified cardiologists and doppler (Echocardiogram) if there is a question on auscultation.  The ACKCSC, Regional Cavalier clubs and local AKC all Breed Clubs are hosting and making health clinics with cardiologists accessible to breeders and owners throughout the USA.   Currently, the recommended practice is to wait until a Cavalier is two years old or older before the first breeding and to know the parents and ancestral cardiac status.  Cavaliers with early onset presentations of MVD (before four years of age) should not be bred and breeders need to work with the guidance of their cardiologists.
Credit for the above information on MVD goes to the American Cavalier King Charles Spaniel Club -

Hip Dysplasia

Hip Dysplasia is a terrible genetic disease because of the various degrees of arthritis (also called degenerative joint disease, arthrosis, osteoarthrosis) it can eventually produce, leading to pain and debilitation.

The very first step in the development of arthritis is articular cartilage (the type of cartilage lining the joint) damage due to the inherited bad biomechanics of an abnormally developed hip joint. Traumatic articular fracture through the joint surface is another way cartilage is damaged. With cartilage damage, lots of degradative enzymes are released into the joint. These enzymes degrade and decrease the synthesis of important constituent molecules that form hyaline cartilage called proteoglycans. This causes the cartilage to lose its thickness and elasticity, which are important in absorbing mechanical loads placed across the joint during movement. Eventually, more debris and enzymes spill into the joint fluid and destroy molecules called glycosaminoglycan and hyaluronate which are important precursors that form the cartilage proteoglycans. The joint's lubrication and ability to block inflammatory cells are lost and the debris-tainted joint fluid loses its ability to properly nourish the cartilage through impairment of nutrient-waste exchange across the joint cartilage cells. The damage then spreads to the synovial membrane lining the joint capsule and more degradative enzymes and inflammatory cells stream into the joint. Full thickness loss of cartilage allows the synovial fluid to contact nerve endings in the subchondral bone, resulting in pain. In an attempt to stabilize the joint to decrease the pain, the animal's body produces new bone at the edges of the joint surface, joint capsule, ligament and muscle attachments (bone spurs). The joint capsule also eventually thickens and the joint's range of motion decreases.

No one can predict when or even if a dysplastic dog will start showing clinical signs of lameness due to pain. There are multiple environmental factors such as caloric intake, level of exercise, and weather that can affect the severity of clinical signs and phenotypic expression (radiographic changes). There is no rhyme or reason to the severity of radiographic changes correlated with the clinical findings. There are a number of dysplastic dogs with severe arthritis that run, jump, and play as if nothing is wrong and some dogs with barely any arthritic radiographic changes that are severely lame.

Patellar Luxation

The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial or lateral position.

Bilateral involvement is most common, but unilateral is not uncommon. Animals can be affected by the time they are 8 weeks of age. The most notable finding is a knock-knee (genu valgum) stance. The patella is usually reducible, and laxity of the medial collateral ligament may be evident. The medial retinacular tissues of the stifle joint are often thickened, and the foot can be seen to twist laterally as weight is placed on the limb.

The Canine Eye Registration Foundation (CERF) is an organization that was founded by a group of concerned, purebred owner/breeders who recognized that the quality of their dog's lives were being affected by heritable eye disease. CERF was then established in conjunction with cooperating, board certified, veterinary ophthalmologists, as a means to accomplish the goal of elimination of heritable eye disease in all purebred and recently hybrid dogs by forming a centralized, national registry.  After the painless physical examination of the dogs eyes, the board certified Veterinary Ophthalmologist will complete the CERF form and indicate any specific disease(s) found.  The exams must be performed once per year on any breeding stock.  To find out more information, go this this website - .  All of our dogs are "CERF'd" annually.

Dry Eye/Curly Coat Syndrome

This disease which is manifested at birth in the Cavalier King Charles Spaniel has symptoms which include reduced tear production and corresponding ocular mucous discharge, as well as a rough coat and scale or alopecia. Later in life, there is an increased chance of dental problems. This syndrome is inherited as an autosomal recessive trait. Researchers at the Animal Health Trust inEngland recently identified the mutation responsible for this syndrome.

Episodic Falling Syndrome

Episodic falling in the Cavalier King Charles Spaniel is an autosomal recessively inherited disease. It is characterized by short, hypertonic episodes in which the limbs of the animal stiffen, often to the point of immobilization. These episodes generally start to occur early in life and can be induced by multiple triggers although excerise and excitement seem to be the most frequent causes. Recently, two research groups independently identified the mutation responsible for this disease.