Cavalier King Charles Spaniel Stud Dog: MVD Protocol, Health Testing, and What to Look For

The Cavalier is one of the most loving breeds ever created — and one of the most health-challenged. Stud selection has never mattered more.

The Cavalier King Charles Spaniel is beloved worldwide for its gentle, affectionate temperament and silky good looks. But the breed carries two of the most serious inherited conditions in all of dog breeding: Mitral Valve Disease (MVD) and Syringomyelia/Chiari-like Malformation (SM/CM). Both are heritable. Both are progressive. Both shorten lives.

The good news: rigorous health testing protocols exist for both conditions, and breeders who follow them are making meaningful progress. Choosing a Cavalier stud without these clearances is not just irresponsible — it actively perpetuates suffering in the breed.

The MVD Breeding Protocol

Mitral Valve Disease affects the vast majority of Cavaliers — studies suggest over 90% are affected by age 10. MVD causes the mitral valve of the heart to degenerate, leading to heart murmurs, heart enlargement, and eventually congestive heart failure.

The MVD Breeding Protocol, developed by the Cavalier Health organization and widely endorsed by Cavalier breed clubs worldwide, establishes minimum requirements for breeding:

The Protocol Requirements

Both parents must be at least 2.5 years old at the time of mating.

Both parents must have a cardiac evaluation by a board-certified cardiologist within the previous 12 months showing:

• No heart murmur, OR
• A murmur no louder than Grade 1 or 2 (in some versions of the protocol)

Both parents of each dog must also have been examined by a cardiologist and found to be clear of MVD at age 2.5 years or older.

This three-generation requirement — testing not just the breeding pair but also their parents — is what makes the protocol powerful. It helps ensure dogs are selected from families where MVD is delayed, not just individuals who happen to be clear at a young age.

Why This Protocol Matters

A Cavalier who develops a heart murmur at age 2 is from a line with earlier-onset MVD than a Cavalier who stays clear until age 8. The protocol selects for later onset, which is the most meaningful way to improve breed health.

A stud dog whose parents were not cardiologist-tested under the protocol, regardless of his own current clearance, does not meet the protocol requirements.

Syringomyelia and Chiari-like Malformation (SM/CM) — MRI Screening

Chiari-like Malformation (CM) is a skull conformation issue in which the back of the skull is too small for the brain. This causes the brain tissue to be pushed into the spinal canal. Syringomyelia (SM) is the result — fluid-filled cavities form in the spinal cord, causing pain, scratching (particularly at the neck and shoulders), and neurological symptoms.

SM/CM is heritable. MRI screening of breeding dogs is the only way to evaluate it.

The BVA/KC/ICSCaSS MRI Scheme

The British Veterinary Association, The Kennel Club (UK), and the International Cavalier King Charles Spaniel Syringomyelia Scheme have developed a grading system:

• CM Grade 0 — No Chiari-like malformation. Ideal.
• CM Grade 1 — Mild CM present. Acceptable for breeding when paired with careful selection.
• SM Negative — No syrinx identified on MRI. Preferred.
• SM Positive — Syrinx present. Affected dogs should not be bred.

MRI screening is expensive ($700-$2,000 depending on location and whether anesthesia is required) but essential for responsible Cavalier breeding.

Age at Screening

SM/CM can develop with age — a dog clear at 18 months may develop SM by age 5. Rescreening at 2.5 years and 5 years is recommended for breeding dogs.

Additional Health Testing for Cavalier Studs

CAER Eye Examination — Annual

Hereditary eye conditions including cataracts occur in Cavaliers. Annual CAER exam is recommended.

Episodic Falling (EF) — DNA Test

EF is a paroxysmal movement disorder in Cavaliers causing episodes of muscle rigidity and falling, triggered by exercise or excitement. A DNA test identifies Clear, Carrier, and Affected dogs. Clear or Carrier studs bred to Clear dams are safe.

Curly Coat/Dry Eye Syndrome (CC/DE) — DNA Test

CC/DE is a condition causing an abnormally dry, curly coat and severe dry eye syndrome. It is DNA testable. Affected dogs should not be bred; Clear and Carrier dogs bred to Clear partners are safe.

What Does a Cavalier Stud Fee Cost?

Cavalier stud fees in 2026 typically range from $800 to $3,000 depending on:

• Full MVD protocol compliance (both parents cardiologist-tested at 2.5+)
• MRI SM/CM clear status
• AKC Championship or UK KC title
• Proven litter quality

Questions to Ask Before Booking

• Are both the stud's parents cardiologist-tested and MVD-clear at 2.5 years or older, per the breeding protocol?
• Has the stud had a cardiologist cardiac evaluation within the past 12 months, and what were the results?
• Has the stud been MRI screened for SM/CM, and what were the grades?
• Has the stud been DNA tested for EF and CC/DE?
• Is he AKC registered?
• Has he produced litters, and can I speak with previous dam owners?
• Will you provide a written stud contract?

Summary

The Cavalier King Charles Spaniel is a breed in real need of responsible breeders. The MVD Breeding Protocol and SM/CM MRI screening exist because dedicated breeders and veterinary researchers developed tools to fight back against this breed's biggest health challenges. A stud who meets the full protocol — cardiologist-tested, MRI screened, DNA tested — is the only stud worth booking.