Cavalier King Charles Spaniel

The Cavalier is the easiest dog on this site to recommend on temperament and the hardest to recommend overall. Almost everything people say about the personality is true: gentle, affectionate without being needy in a difficult way, tolerant of children, quiet, adaptable to a flat, happy to walk for an hour or curl up for an afternoon.

Then there is the health, and it cannot be a footnote. Two serious inherited conditions run through this breed at rates that are not comparable to most other dogs, and anyone choosing a Cavalier deserves to know that before they meet a puppy, because after they meet a puppy it is too late to think clearly.

The heart problem, stated plainly

Mitral valve disease is a degeneration of one of the heart’s valves. It occurs in many older small dogs. In Cavaliers it occurs far more, and far earlier.

The pattern is well documented: a murmur appears, often in a dog still in early middle age, and progresses over years towards heart failure. The great majority of Cavaliers that live long enough develop it, and it is the leading cause of death in the breed.

What that means practically:

• Annual heart checks from early adulthood, not from old age. A murmur found early is a dog monitored and medicated at the right time, and treatment does extend good years.
• Ask breeders about cardiac testing specifically. There are established protocols involving annual specialist heart examination of breeding stock and not breeding young dogs. A breeder who follows one will tell you the details without being pushed. A breeder who says the parents are “healthy” is telling you nothing.
• Keep the dog lean. It is the one variable entirely in your hands, and weight makes a failing heart work harder.

None of this makes the breed a bad choice. It makes it a choice you should make with the facts.

Syringomyelia, and the sign to know

The second condition is harder to explain and easier to miss. The Cavalier skull is, in many dogs, too small for the brain it contains. That obstructs the normal flow of spinal fluid, and fluid-filled cavities form within the spinal cord.

The recognisable sign is odd and specific: scratching towards the neck or shoulder without making contact, often while walking, sometimes called air scratching. Others include yelping when lifted or on waking, reluctance to have the head or neck touched, and sensitivity that comes and goes.

Severity varies enormously. Many affected dogs are mildly affected and live comfortably. Some are in real pain and need long-term medication. Diagnosis needs an MRI, which is why estimates vary and why a vague reassurance from a seller is worth nothing.

If you see air scratching in any Cavalier, mention it to your vet by name. It is easily dismissed as a habit.

What living with one is actually like

Genuinely lovely, and genuinely dependent.

Cavaliers were bred for one job across several centuries: being with people. They did it so well that many struggle when the people go. This is one of the breeds where an eight-hour empty house is a welfare question rather than an inconvenience, and our guides to how long a dog can be left alone and separation anxiety are worth reading before you commit, not after.

They are quiet, which makes them a strong flat dog and puts them on our apartment-friendly list. They are tolerant with children in a way that many small breeds are not, which is why they turn up in our family breeds guide as well.

The spaniel underneath is real, though. Many will chase a bird or a squirrel across a road without hesitating, so recall work and a sensible attitude to off-lead time matter more than the lapdog image suggests.

Everyday care

The silky coat needs brushing two or three times a week, with attention to the feathering behind the ears and on the legs where it mats. No clipping required.

Ears need checking as routine. Long, heavy and warm is the combination that produces infections.

Weight is the thing to stay strict about. A Cavalier will eat whatever is offered and looks appealing while doing it, and the consequences land on a heart that is statistically likely to need every advantage. Our dog food calculator gives a daily figure, and weighing rather than eyeballing portions is worth the twenty seconds.

If you are set on the breed

Two questions, asked directly, tell you most of what you need:

1. What heart testing have the parents had, at what age, and by whom? You want annual specialist cardiac examination, and you want to see it.
2. Has either parent been MRI scanned? Many have not. A breeder who says so honestly, and explains what they do instead, is being straighter than one who waves the question away.

Rescue is also worth considering seriously here. Cavaliers come into rescue for the usual human reasons, they adapt well to new homes given their temperament, and an adult dog’s heart status is a known quantity rather than a probability.