Our latest project, The Cavalier Composition: A Practical Guide to Cavalier Health, will be published in 2026.
CAVALIER KING CHARLES SPANIEL HEALTH & BREEDING
Breeding Cavalier King Charles Spaniels is a lifelong responsibility that requires thoughtful planning, continued learning, and an honest understanding of what health testing can (and cannot) tell us. With more than 35 years of experience with Cavaliers, our approach combines health screening, veterinary care, pedigree knowledge, genetic testing, ongoing monitoring, and careful breeding decisions, with a strong focus on the health, welfare, and future of the breed.
Our commitment to Cavalier health extends beyond individual testing. We believe responsible breeding requires transparency, continued education, collaboration with veterinary professionals, careful evaluation of each dog, and a willingness to adapt as veterinary knowledge and genetic science continue to evolve. Our goal is to use the information available to us thoughtfully while recognizing the limitations of any individual test, screening method, or breeding decision.
HISTORICAL CAVALIERS VERSUS MODERN CAVALIERS
The modern Cavalier King Charles Spaniel was developed in the early 20th century through efforts to recreate the longer-nosed toy spaniels seen in historic paintings from the time of King Charles II. These dogs differed from the shorter-faced English Toy Spaniel that had developed as breed type and fashion changed over the centuries.
In the 1920s, American enthusiast Roswell Eldridge offered prizes at Crufts for breeders who could produce dogs resembling the earlier “old-type” spaniels, with longer muzzles, flatter skulls, and a more moderate structure. These efforts played an important role in the development of the modern Cavalier King Charles Spaniel.
Understanding how the modern Cavalier population developed is particularly important when discussing genetics, inherited health conditions, and genetic diversity. The breed's later history, including the dramatic reduction in breeding populations during World War II, created challenges that continue to influence Cavalier health and responsible breeding decisions today.
WORLD WAR II AND THE MODERN CAVALIER GENE POOL
Like many breeds in Europe, the Cavalier King Charles Spaniel faced an uncertain future during World War II. Food shortages, wartime restrictions, and the realities of survival dramatically reduced breeding populations across England, leaving relatively few Cavaliers available to help rebuild the breed after the war.
As dedicated breeders worked to restore the Cavalier population, this limited number of surviving dogs became an important part of the foundation of the modern breed. As a result, today's Cavaliers descend from a comparatively narrow genetic base, creating a historical population bottleneck that has contributed to reduced genetic diversity within the breed.
This history is important when discussing inherited health conditions and responsible Cavalier breeding. When genetic diversity is limited, simply removing every dog associated with a particular health concern can further narrow the gene pool and may unintentionally increase other genetic risks. Responsible breeding therefore requires balancing health screening, pedigree and family history, genetic diversity, structure, temperament, and the overall qualities of each individual dog.
No single health test, DNA panel, or breeding strategy can eliminate every inherited risk. Our goal is to use all available information thoughtfully, make informed breeding decisions, monitor our dogs throughout their lives, and continue adapting as veterinary medicine and genetic science advance.
CARDIAC HEALTH AND ONGOING MONITORING
Heart health is one of the most important health considerations in the Cavalier King Charles Spaniel. Our breeding dogs receive regular cardiac evaluations, including annual cardiac screenings and ECG monitoring to evaluate heart rhythm and overall cardiac function.
Because cardiac status can change as a dog ages, these evaluations are repeated throughout a dog's breeding years rather than relying on a single clearance. A normal cardiac evaluation is valuable information, but it represents the dog's heart health at that particular point in time.
This ongoing monitoring helps us follow cardiac health as our dogs mature and provides additional information to consider alongside pedigree history, family longevity, and other factors when making breeding decisions.
MITRAL VALVE DISEASE (MVD) IN CAVALIER KING CHARLES SPANIELS
Mitral valve disease (MVD), also known as myxomatous mitral valve disease (MMVD), is one of the most important health concerns affecting the Cavalier King Charles Spaniel. The condition involves degeneration of the mitral valve, which can allow blood to leak backward through the valve and commonly results in the development of a heart murmur.
MVD is particularly significant in Cavaliers because of its high prevalence within the breed. However, the age of onset, rate of progression, and clinical impact can vary considerably from one dog to another. Some Cavaliers may develop a murmur and remain clinically well for years, while others may experience more significant progression requiring veterinary monitoring and treatment.
MVD is a complex condition that cannot currently be predicted or eliminated through a single DNA test. This makes long-term knowledge of individual dogs and their families especially valuable when evaluating breeding decisions. Cardiac history, age of onset, longevity, pedigree, genetic diversity, and the overall health of both the individual dog and its relatives can all contribute useful information.
For us, responsible breeding means recognizing both the importance of MVD and the limitations of the tools currently available to predict it. Our goal is to use cardiac monitoring, family history, pedigree knowledge, and evolving veterinary and genetic information together to make thoughtful breeding decisions while continuing to follow the health and longevity of our Cavaliers across generations.
GENETIC TESTING AND RESPONSIBLE USE OF DNA
DNA testing is an important part of our Cavalier health program because it can identify specific inherited genetic variants and, unlike many physical health screenings, a dog's DNA results do not change over its lifetime.
We use comprehensive DNA testing to help identify known and testable genetic risks and to make informed breeding decisions. Results are considered alongside veterinary examinations, cardiac and eye evaluations, pedigree and family history, structure, temperament, and the genetic profile of a potential breeding partner.
DNA testing is an extremely valuable tool, but it cannot guarantee that a dog or its offspring will never develop a health condition. Many important health concerns in Cavalier King Charles Spaniels, including mitral valve disease (MVD), are complex conditions that cannot currently be predicted or eliminated through a single DNA test.
For that reason, we believe responsible genetic testing is not simply about obtaining a list of “clear” results. It is about understanding those results and using them thoughtfully as one part of a broader, long-term approach to Cavalier health and responsible breeding.
OPHTHALMOLOGY AND EYE HEALTH MONITORING
Eye health is monitored throughout our dogs' lives as part of their routine veterinary care. Our veterinarian performs regular eye checks during annual wellness examinations to monitor general ocular health and identify changes that may warrant further evaluation.
Our breeding dogs also receive CAER (Companion Animal Eye Registry) examinations performed by a veterinary ophthalmologist. These specialized examinations evaluate the eyes for inherited and other ocular abnormalities that may be relevant to breeding decisions.
By combining routine veterinary monitoring with specialized ophthalmic examinations, we are able to follow eye health over time and incorporate those findings into our broader health and breeding program.
ORTHOPEDIC EVALUATION AND STRUCTURAL SOUNDNESS
Orthopedic health and structural soundness are important considerations in our Cavalier breeding program. Our board-certified veterinarian, a published author with specialized training and expertise in mobility, rehabilitation, regenerative medicine, and orthopedic care, performs comprehensive orthopedic evaluations of our breeding dogs.
These evaluations include examination of the patellas, knees, elbows, joints, movement, and overall musculoskeletal structure. Regular evaluation as our dogs mature allows us to monitor joint stability and structural soundness over time rather than relying solely on a single examination.
Orthopedic findings are considered alongside our dogs' overall health, pedigree and family history, structure, movement, and other health information when making breeding decisions.
TEMPERAMENT AND DEVELOPMENT
Health and responsible breeding involve more than physical testing. The Cavalier King Charles Spaniel should possess the affectionate, gentle, stable, and adaptable temperament for which the breed is known.
Temperament is considered when evaluating our breeding dogs, alongside physical health, structure, pedigree, and other factors. Our puppies are raised with human interaction beginning at birth, followed by age-appropriate socialization and exposure as they develop.
Our goal is to support the natural qualities of the breed while helping our puppies develop into confident, well-adjusted companions prepared for life with their families.
GENETIC DIVERSITY AND THOUGHTFUL PLANNING
Because genetic diversity is an important consideration within the Cavalier King Charles Spaniel breed, thoughtful pedigree planning is an essential part of our breeding program. We evaluate pedigrees and family history alongside health information, structure, temperament, and genetic testing when considering potential pairings.
Our goal is not simply to select dogs based on an individual test result, but to consider the whole dog and the potential pairing. Maintaining genetic diversity while making responsible health decisions requires balance, particularly in a breed with a relatively limited gene pool.
By studying pedigrees, generations of family history, and the characteristics of both the sire and dam, we work to make informed breeding decisions that support health, soundness, temperament, breed type, and the long-term future of the Cavalier King Charles Spaniel.
AGE-APPROPRIATE BREEDING PRACTICES
We believe maturity matters. Our breeding dogs are evaluated over time and are not bred until they are old enough for meaningful health screening and physical maturity.
Health information gathered as a dog matures can provide a clearer picture than relying only on very early evaluations. For that reason, we continue to re-evaluate our dogs throughout their breeding years and consider age, physical development, health history, pedigree, temperament, structure, and overall condition when making breeding decisions.
Responsible breeding is not based on a single test or a single moment in time. It is an ongoing process of evaluation, observation, and careful decision-making as each dog develops.
OUR HEALTH GUARANTEE AND LIFELONG FOLLOW-UP
Our commitment to our Cavaliers does not end when a puppy leaves our care. Every Royal Flush Cavaliers® puppy is placed with our Cavalier Five-Year™ Health Guarantee, which includes extended cardiac coverage as outlined in the written agreement.
We encourage our families to maintain regular veterinary care and pet insurance throughout their Cavalier's life, including routine wellness examinations and ongoing cardiac monitoring. Staying in contact with our families also provides valuable long-term information about the health and longevity of dogs produced through our breeding program.That continued feedback helps us follow our bloodlines across generations and provides additional information that can be considered when making future breeding decisions.
Breeding Cavalier King Charles Spaniels is a lifelong responsibility that requires thoughtful planning, continued learning, and an honest understanding of what health testing can (and cannot) tell us. With more than 35 years of experience with Cavaliers, our approach combines health screening, veterinary care, pedigree knowledge, genetic testing, ongoing monitoring, and careful breeding decisions, with a strong focus on the health, welfare, and future of the breed.
Our commitment to Cavalier health extends beyond individual testing. We believe responsible breeding requires transparency, continued education, collaboration with veterinary professionals, careful evaluation of each dog, and a willingness to adapt as veterinary knowledge and genetic science continue to evolve. Our goal is to use the information available to us thoughtfully while recognizing the limitations of any individual test, screening method, or breeding decision.
HISTORICAL CAVALIERS VERSUS MODERN CAVALIERS
The modern Cavalier King Charles Spaniel was developed in the early 20th century through efforts to recreate the longer-nosed toy spaniels seen in historic paintings from the time of King Charles II. These dogs differed from the shorter-faced English Toy Spaniel that had developed as breed type and fashion changed over the centuries.
In the 1920s, American enthusiast Roswell Eldridge offered prizes at Crufts for breeders who could produce dogs resembling the earlier “old-type” spaniels, with longer muzzles, flatter skulls, and a more moderate structure. These efforts played an important role in the development of the modern Cavalier King Charles Spaniel.
Understanding how the modern Cavalier population developed is particularly important when discussing genetics, inherited health conditions, and genetic diversity. The breed's later history, including the dramatic reduction in breeding populations during World War II, created challenges that continue to influence Cavalier health and responsible breeding decisions today.
WORLD WAR II AND THE MODERN CAVALIER GENE POOL
Like many breeds in Europe, the Cavalier King Charles Spaniel faced an uncertain future during World War II. Food shortages, wartime restrictions, and the realities of survival dramatically reduced breeding populations across England, leaving relatively few Cavaliers available to help rebuild the breed after the war.
As dedicated breeders worked to restore the Cavalier population, this limited number of surviving dogs became an important part of the foundation of the modern breed. As a result, today's Cavaliers descend from a comparatively narrow genetic base, creating a historical population bottleneck that has contributed to reduced genetic diversity within the breed.
This history is important when discussing inherited health conditions and responsible Cavalier breeding. When genetic diversity is limited, simply removing every dog associated with a particular health concern can further narrow the gene pool and may unintentionally increase other genetic risks. Responsible breeding therefore requires balancing health screening, pedigree and family history, genetic diversity, structure, temperament, and the overall qualities of each individual dog.
No single health test, DNA panel, or breeding strategy can eliminate every inherited risk. Our goal is to use all available information thoughtfully, make informed breeding decisions, monitor our dogs throughout their lives, and continue adapting as veterinary medicine and genetic science advance.
CARDIAC HEALTH AND ONGOING MONITORING
Heart health is one of the most important health considerations in the Cavalier King Charles Spaniel. Our breeding dogs receive regular cardiac evaluations, including annual cardiac screenings and ECG monitoring to evaluate heart rhythm and overall cardiac function.
Because cardiac status can change as a dog ages, these evaluations are repeated throughout a dog's breeding years rather than relying on a single clearance. A normal cardiac evaluation is valuable information, but it represents the dog's heart health at that particular point in time.
This ongoing monitoring helps us follow cardiac health as our dogs mature and provides additional information to consider alongside pedigree history, family longevity, and other factors when making breeding decisions.
MITRAL VALVE DISEASE (MVD) IN CAVALIER KING CHARLES SPANIELS
Mitral valve disease (MVD), also known as myxomatous mitral valve disease (MMVD), is one of the most important health concerns affecting the Cavalier King Charles Spaniel. The condition involves degeneration of the mitral valve, which can allow blood to leak backward through the valve and commonly results in the development of a heart murmur.
MVD is particularly significant in Cavaliers because of its high prevalence within the breed. However, the age of onset, rate of progression, and clinical impact can vary considerably from one dog to another. Some Cavaliers may develop a murmur and remain clinically well for years, while others may experience more significant progression requiring veterinary monitoring and treatment.
MVD is a complex condition that cannot currently be predicted or eliminated through a single DNA test. This makes long-term knowledge of individual dogs and their families especially valuable when evaluating breeding decisions. Cardiac history, age of onset, longevity, pedigree, genetic diversity, and the overall health of both the individual dog and its relatives can all contribute useful information.
For us, responsible breeding means recognizing both the importance of MVD and the limitations of the tools currently available to predict it. Our goal is to use cardiac monitoring, family history, pedigree knowledge, and evolving veterinary and genetic information together to make thoughtful breeding decisions while continuing to follow the health and longevity of our Cavaliers across generations.
GENETIC TESTING AND RESPONSIBLE USE OF DNA
DNA testing is an important part of our Cavalier health program because it can identify specific inherited genetic variants and, unlike many physical health screenings, a dog's DNA results do not change over its lifetime.
We use comprehensive DNA testing to help identify known and testable genetic risks and to make informed breeding decisions. Results are considered alongside veterinary examinations, cardiac and eye evaluations, pedigree and family history, structure, temperament, and the genetic profile of a potential breeding partner.
DNA testing is an extremely valuable tool, but it cannot guarantee that a dog or its offspring will never develop a health condition. Many important health concerns in Cavalier King Charles Spaniels, including mitral valve disease (MVD), are complex conditions that cannot currently be predicted or eliminated through a single DNA test.
For that reason, we believe responsible genetic testing is not simply about obtaining a list of “clear” results. It is about understanding those results and using them thoughtfully as one part of a broader, long-term approach to Cavalier health and responsible breeding.
OPHTHALMOLOGY AND EYE HEALTH MONITORING
Eye health is monitored throughout our dogs' lives as part of their routine veterinary care. Our veterinarian performs regular eye checks during annual wellness examinations to monitor general ocular health and identify changes that may warrant further evaluation.
Our breeding dogs also receive CAER (Companion Animal Eye Registry) examinations performed by a veterinary ophthalmologist. These specialized examinations evaluate the eyes for inherited and other ocular abnormalities that may be relevant to breeding decisions.
By combining routine veterinary monitoring with specialized ophthalmic examinations, we are able to follow eye health over time and incorporate those findings into our broader health and breeding program.
ORTHOPEDIC EVALUATION AND STRUCTURAL SOUNDNESS
Orthopedic health and structural soundness are important considerations in our Cavalier breeding program. Our board-certified veterinarian, a published author with specialized training and expertise in mobility, rehabilitation, regenerative medicine, and orthopedic care, performs comprehensive orthopedic evaluations of our breeding dogs.
These evaluations include examination of the patellas, knees, elbows, joints, movement, and overall musculoskeletal structure. Regular evaluation as our dogs mature allows us to monitor joint stability and structural soundness over time rather than relying solely on a single examination.
Orthopedic findings are considered alongside our dogs' overall health, pedigree and family history, structure, movement, and other health information when making breeding decisions.
TEMPERAMENT AND DEVELOPMENT
Health and responsible breeding involve more than physical testing. The Cavalier King Charles Spaniel should possess the affectionate, gentle, stable, and adaptable temperament for which the breed is known.
Temperament is considered when evaluating our breeding dogs, alongside physical health, structure, pedigree, and other factors. Our puppies are raised with human interaction beginning at birth, followed by age-appropriate socialization and exposure as they develop.
Our goal is to support the natural qualities of the breed while helping our puppies develop into confident, well-adjusted companions prepared for life with their families.
GENETIC DIVERSITY AND THOUGHTFUL PLANNING
Because genetic diversity is an important consideration within the Cavalier King Charles Spaniel breed, thoughtful pedigree planning is an essential part of our breeding program. We evaluate pedigrees and family history alongside health information, structure, temperament, and genetic testing when considering potential pairings.
Our goal is not simply to select dogs based on an individual test result, but to consider the whole dog and the potential pairing. Maintaining genetic diversity while making responsible health decisions requires balance, particularly in a breed with a relatively limited gene pool.
By studying pedigrees, generations of family history, and the characteristics of both the sire and dam, we work to make informed breeding decisions that support health, soundness, temperament, breed type, and the long-term future of the Cavalier King Charles Spaniel.
AGE-APPROPRIATE BREEDING PRACTICES
We believe maturity matters. Our breeding dogs are evaluated over time and are not bred until they are old enough for meaningful health screening and physical maturity.
Health information gathered as a dog matures can provide a clearer picture than relying only on very early evaluations. For that reason, we continue to re-evaluate our dogs throughout their breeding years and consider age, physical development, health history, pedigree, temperament, structure, and overall condition when making breeding decisions.
Responsible breeding is not based on a single test or a single moment in time. It is an ongoing process of evaluation, observation, and careful decision-making as each dog develops.
OUR HEALTH GUARANTEE AND LIFELONG FOLLOW-UP
Our commitment to our Cavaliers does not end when a puppy leaves our care. Every Royal Flush Cavaliers® puppy is placed with our Cavalier Five-Year™ Health Guarantee, which includes extended cardiac coverage as outlined in the written agreement.
We encourage our families to maintain regular veterinary care and pet insurance throughout their Cavalier's life, including routine wellness examinations and ongoing cardiac monitoring. Staying in contact with our families also provides valuable long-term information about the health and longevity of dogs produced through our breeding program.That continued feedback helps us follow our bloodlines across generations and provides additional information that can be considered when making future breeding decisions.