The Cavalier is the largest toy breed. They are highly affectionate, and some have called the Cavalier King Charles Spaniel "the ultimate lap dog", although a fully-grown adult tends to fill one rather amply.

As a breed there are four recognised colours:

• Blenheim (rich chestnut on pearly white background)
• Tricolour (black and white with tan markings on cheeks, inside ears, resembling eyebrows, inside legs, and on underside of tail)
• Black and Tan (black with tan markings)
• Ruby (rich reddish-brown all over)

Most are playful, extremely patient and eager to please. As such, they are usually good with children and other dogs. A well-socialized Cavalier will not be shy about socializing with much larger dogs. (However, on occasion, this tendency can be dangerous, as many cavaliers will presume all other dogs to be equally friendly, and may attempt to greet and play with aggressive dogs).

The history

For many centuries, small breeds of spaniels have been popular in the United Kingdom. In the eleventh century, in the reign of King Canute, it was illegal to hunt with any dog that could not fit through a gauge that was eleven inches in diameter. Hence, the "birth" of the Toy Spaniel in the United Kingdom. Some centuries later, Toy Spaniels became popular as pets, especially as pets of the royal family. In fact, the King Charles Spaniel was so named because a Blenheim-coated spaniel was the children's pet in the household of Charles I. King Charles II went so far as to issue a decree that the King Charles Spaniel could not be forbidden entrance to any public place, including the Houses of Parliament. Such spaniels can be seen in many paintings of the 16th, 17th and 18th centuries. These early spaniels had longer, pointier snouts and thinner-boned limbs than today's.

Over time, the toy spaniels were replaced in popularity by short-snouted, dome-headed dogs of asian descent, such as the Pug and Japanese Chin. The King Charles Spaniel was bred with these dogs, resulting in the similar-shaped head of today's English Toy Spaniel breed. The King Charles Spaniel remained popular at Blenheim Palace, home to the Dukes of Marlborough, where the brown and white version was the most popular - resulting in the name Blenheim for that colour combination.

In the 1920s, an American named Roswell Eldrige offered twenty-five pounds as a prize for any King Charles Spaniel "of the old-fashioned type" with a longer nose, flat skull, and a lozenge (spot) in the middle of the crown of the head, sometimes called "the kiss of Buddha," "Blenheim Spot," or "Kissing Spot". So, the breed was developed by selective breeding of short-snouted Spaniels. The result was a dog that resembled the boyhood pet of the future Charles II of England ("Cavalier King Charles"), whence the breed derives its name.

Two breed clubs/registries are found in the United States: the Cavalier King Charles Spaniel Club (CKCSC) USA and the American Cavalier King Charles Spaniel Club. The latter club is the breed club of the American Kennel Club.

Care

That beautiful silky coat requires daily careful combing and brushing to prevent matting.

They are intelligent and respond well to regular walks and training.

Spaniels are sporting dogs and even the Cavalier needs mental stimulation.

Health

The breed suffers from a number of severe genetic defects. If considering a puppy, ask to see its parents' heart and eye certificates to reduce the chance your puppy will have the defects described below. Many breeders supply these and most breeders choose pairings to try to reduce the incidence of these defects in the breed.

Mitral valve disease

Virtually all Cavaliers suffer from mitral valve disease, causing progressively worsening heart murmurs leading to heart failure. This condition can begin to emerge at an early age, and is present in more than half of all Cavalier King Charles Spaniels by 5 years of age. It is extremely rare for a 10-year-old Cavalier not to have at least a slight heart murmur. It is the leading cause of death of the Cavalier King Charles Spaniel. Veterinary geneticists and cardiologists have designed breeding guidelines to eliminate early-onset mitral valve disease in the breed, but only an insignificant minority of breeders follow these guidelines.

Syringomyelia

Syringomyelia (SM) is a condition affecting the brain and spine, causing symptoms ranging from mild discomfort to severe pain and partial paralysis. Syringomyelia is rare in most breeds but has become widespread in the Cavalier King Charles Spaniel. Veterinary neurologists who have been researching the disease in Cavaliers have estimated that at least half of all Cavaliers have either syringomyelia or occipital hypoplasia, the skull bone malformation believed to cause SM. The 2005 Cavalier Heath Survey done by the AKC Cavalier club indicated that about 4% of Cavaliers showed clinical symptoms consistent with SM. Although symptoms of syringomyelia can present at any age, they typically appear between 6 months and 3 years of age. Symptoms include sensitivity around the head, neck, or shoulders, often indicated by a dog whimpering or frequently scratching at the area of his neck or shoulder. Scratching is often unilateral -- restricted to one side of the body. Scratching motions are frequently performed without actually making physical contact with the body. The scratching behaviour appears involuntary and the dog frequently scratches while walking -- without stopping -- in a way that is very atypical of normal scratching. Scratching typical of SM is usually worse when the dog is wearing a collar, is being walked on leash, or is excited.

Not all dogs with SM show scratching behaviour. Not all dogs who show scratching behaviour appear to suffer pain. If onset is at an early age, the first sign may be rapidly appearing scoliosis. If the problem is severe, there is likely to be poor proprioception (awareness of body position), especially with regard to the forelimbs. Clumsiness and falling results from this problem.

A vet should be asked to rule out primary secretory otitis media (PSOM - glue ear) before assuming that a Cavalier has SM. PSOM can present similar symptoms but is much easier and cheaper to treat. An MRI scan is normally done to confirm diagnosis of SM.

Episodic Falling (EF)

Episodic Falling is an 'exercise-induced paroxysmal hypertonicity disorder' meaning that there is increased muscle tone in the dog and the muscles are unable to relax. Although it is often misdiagnosed as epilepsy, the dog remains conscious throughout the episode. Severity of symptoms can range from mild, occasional falling or freezing to seizure-like episodes lasting hours. Episodes can become more or less severe as the dog gets older. Onset of symptoms is usually before five months but may be noticed only later in life. See http://www.episodicfalling.com/ for more information and support.

Hip dysplasia

Hip dysplasia is a common genetic disease in the Cavalier King Charles Spaniel. It rarely is present at birth and develops with age. Hip dysplasia is diagnosed by x-rays, but it usually does not appear in x-rays of Cavaliers until they mature.

Luxating patella

Cavaliers, like many toy breeds, are subject to a genetic defect of the femur and knee called luxating patella. The disorder is believed to affect 20% to 30% of Cavalier King Charles Spaniels. This condition is most often observed when a puppy is 4 to 6 months old. In the most serious cases, surgery may be indicated.

Keratoconjunctivitis Sicca

Another common defect among Cavaliers is keratoconjunctivitis sicca, colloquially known as "dry eye". The usual cause of this condition is an autoimmune reaction against the dog's lacrimal gland (tear gland), reducing the production of tears. The condition requires continual treatment and if untreated may result in partial or total blindness.