An exceptional temperament attached to two serious inherited conditions
The Cavalier King Charles Spaniel is, temperamentally, close to ideal as a companion. It is affectionate without being demanding, gentle with children, sociable with other dogs, adaptable to apartments, and biddable enough to train easily. There is a reason it is one of the most recommended small breeds for families and for older owners.
Its health profile is a different matter, and it is documented well enough that a prospective owner can and should make an informed decision rather than a hopeful one. Everything below is screenable, and the difference between a well-bred Cavalier and a casually bred one is larger in this breed than in almost any other.
Mitral valve disease — the defining condition
Myxomatous mitral valve disease is a degenerative disease of the heart’s mitral valve. In the Cavalier King Charles Spaniel its prevalence is roughly twenty times that of other breeds, and it appears far earlier.
The published figures are worth stating plainly. About half of Cavaliers have a heart murmur by five years of age, and nearly all surviving Cavaliers have one by ten (UFAW summary of UK and US studies). This is not an uncommon complication; it is the expected trajectory of the breed.
What can be done about it — and it is a lot
Screening demonstrably works. A study of mandatory breeding schemes based on auscultation and echocardiography found that breeding restrictions significantly decreased the prevalence of the disease over an eight-to-ten-year period. The established protocol holds that no Cavalier should be bred under 2.5 years of age with a heart certified clear by a veterinary cardiologist, and ideally with its own parents clear at five.
So the question to a breeder is specific, and it is not optional: have both parents been auscultated by a veterinary cardiologist, at what age, and may I see the certificates? Anything vaguer than a document with a cardiologist’s name on it is not an answer.
As an owner: from about five years of age, ask your vet to listen to the heart at every annual visit rather than only when something seems wrong. A murmur detected early is a monitoring plan and, at the appropriate stage, medication that meaningfully delays the onset of heart failure. A murmur detected at the point of coughing, exercise intolerance and breathlessness is a management problem instead.
Chiari-like malformation and syringomyelia
The second inherited condition is neurological. The skull is too small for the brain it contains, crowding the hindbrain and disrupting the flow of cerebrospinal fluid, which can produce fluid-filled cavities within the spinal cord. MRI screening studies of 1,020 and 555 Cavaliers found syringomyelia in 39% and 46% of dogs (reviewed in Limpens et al., Frontiers in Veterinary Science, 2024).
It is diagnosed by MRI, and screening protocols recommend imaging at three years or older. MRI-based screening programmes in Denmark and the Netherlands reduced mean prevalence in the screened population from about 38% to 27% across two five-year periods — a real improvement, though a modest one, which tells you how deeply embedded the condition is (Limpens et al., 2024).
The signs owners miss
Syringomyelia is routinely mistaken for a behavioural quirk. Watch for:
- Air-scratching — scratching at the neck or shoulder, often on one side, without actually making contact, frequently while walking
- Yelping when picked up, when the collar is touched, or apparently at nothing
- Sensitivity around the head, neck and ears; reluctance to be handled there
- Discomfort that seems worse at night, on waking, or in cold weather
If your Cavalier does this, it warrants a veterinary neurological opinion rather than a training intervention. The condition is painful and there are genuine management options.
Use a harness rather than a collar for this breed as a matter of course.
The rest
Patellar luxation is graded I to IV, with grades II and above often requiring surgery. Drop ears with feathering make otitis externa a recurring theme — check weekly, dry thoroughly after baths. Hip dysplasia is screened radiographically. Eye conditions including dry eye and cataracts occur; ask about eye certification.
Exercise, weight and temperament
Thirty minutes of daily activity suits a moderate-energy companion dog. The Cavalier is adaptable and will happily do more or less — which is exactly why obesity is common in the breed. That matters more here than in most small dogs, because excess weight adds direct load to a heart that is statistically likely to be compromised. Keeping a Cavalier lean is genuine cardiac care.
This is a dog bred to be in a person’s company. It does not cope well with long days alone, and separation distress is best prevented from the first week with gradual, unremarkable absences rather than treated later.
Coat and Australian conditions
The medium silky coat sheds moderately and needs brushing several times a week, with attention to the ear feathering, the chest and behind the legs where mats form. Professional grooming every eight to ten weeks keeps it manageable. Check between the toes and inside the ear leathers for grass seeds after walks in dry paddock country.
In summer, exercise early or late and carry water — and be particularly conservative with a dog that has a known heart murmur, since heat and exertion both increase cardiac demand.
Ownership in Australia
In Victoria, microchipping and council registration are required from three months of age under the Domestic Animals Act 1994, renewing annually on 10 April. Desexed registration across the Victorian councils in our fee survey ranged from about $19.50 to $93.30 a year.
The honest summary: this is a wonderful dog with two well-documented and screenable inherited diseases. Buying from a breeder who screens for both, and monitoring the heart annually from middle age, is not excessive caution — it is the entire difference between the good version of owning this breed and the difficult one.
Registration is set by your local council. In Victoria, registering a desexed Cavalier King Charles Spaniel costs between $19.50 and $93.30 a year depending on where you live, and roughly three times that if the dog is not desexed. See every Victorian council’s 2026–27 fee, or compare registration costs in every state.
Related breeds
The Cavalier King Charles Spaniel, originating from the United Kingdom, is a small breed classified under the 'Toys' group. With an average lifespan of 9 to 14 years, their health complexity score is 2.0. Weighing between 5 to 8 kg, they have a medium, silky, smooth coat that requires weekly maintenance. Not hypoallergenic, they shed moderately. Their temperament includes high sociability and low-reactivity, making them highly paediatric-compatible and excellent with other pets. They require 30 minutes of daily exercise and are moderately prone to separation anxiety. Obesity risk is high, and key health issues include Mitral Valve Disease, Syringomyelia, Hip Dysplasia, Patellar Luxation, and Ear Infections. Ranked 44th in intelligence, they are amongst the top 30 most popular breeds in Australia. Annual veterinary costs are estimated at $1360, not including food and coat maintenance.
Due to their health complexity, Cavalier King Charles Spaniels are prone to Mitral Valve Disease, Syringomyelia, Hip Dysplasia, Patellar Luxation, and Ear Infections. Regular veterinary checkups should include cardiac assessments, neurological evaluations, and joint health monitoring.
Daily care involves 30 minutes of exercise such as walking or supervised play. Weekly coat maintenance protocols include brushing and occasional baths to maintain coat health. Regular ear checks and dental hygiene are recommended. Ensure a balanced diet to mitigate the high risk of obesity.
