The Cavalier King Charles Spaniel is a small spaniel classed as a toy dog by The Kennel Club. It is one of the most popular breeds in the United Kingdom. Since 2000, it has grown in popularity in the United States. It is a smaller breed of spaniel, and Cavalier adults are often the same size as adolescent dogs of other spaniel breeds. It has a silky, smooth coat and commonly a smooth Docking tail. The breed standard recognizes four colours: Blenheim, Tricolour (black/white/tan), Black and Tan, and Ruby. The breed is generally friendly, affectionate and good with both children and other animals; however, they require a lot of human interaction.The King Charles changed drastically in the late 17th century, when it was interbred with flat-nosed breeds. Until the 1920s, the Cavalier shared the same history as the smaller King Charles Spaniel. Breeders attempted to recreate what they considered to be the original configuration of the breed, a dog resembling Charles II of England's King Charles Spaniel of the English Restoration. Various health issues affect this particular breed.
During the early part of the 18th century, John Churchill, 1st Duke of Marlborough, kept red and white King Charles type spaniels for hunting. The duke recorded that they were able to keep up with a trotting horse. His estate was named Blenheim Palace in honour of his victory at the Battle of Blenheim. Because of this influence, the red and white variety of the King Charles Spaniel and thus the Cavalier King Charles Spaniel became known as the Blenheim.Attempts were made to recreate the original King Charles Spaniel as early as the turn of the 20th century, using the now extinct Toy Trawler Spaniels. These attempts were documented by Judith Blunt-Lytton, 16th Baroness Wentworth, in the book "Toy Dogs and Their Ancestors Including the History And Management of Toy Spaniels, Pekingese, Japanese and Pomeranians" published under the name of the "Hon. Mrs Neville Lytton" in 1911.
Divergence from King Charles Spaniel
In 1926, American Roswell Eldridge offered a dog show class prize of twenty-five pounds each as a prize for the best male and females of "Blenheim Spaniels of the old type, as shown in pictures of Charles II of England's time, long face, no stop, flat skull, not inclined to be domed, with spot in centre of skull." and The Kennel Club recognised the breed as "King Charles Spaniels, Cavalier type".
Cavaliers can often suffer from, most notably mitral valve disease, which leads to heart failure. This appears in most Cavaliers at some point in their lives and is the most common cause of death. Some serious genetic health problems, including early-onset mitral valve disease (MVD), the potentially severely painful syringomyelia (SM), hip dysplasia (canine), luxating patellas, and certain vision and hearing disorders are health problems for this breed. . As today's Cavaliers all descend from only six dogs, any inheritable disease present in at least one of the original founding dogs can be passed on to a significant proportion of future generations. This is known as the founder effect and is the likely cause of the prevalence of MVD in the breed. The health problems shared with this breed include mitral valve disease, luxating patella, and hereditary eye issues such as cataracts and retinal dysplasia.
Cavaliers are also affected by ear problems, a common health problem among spaniels of various types, and they can suffer from such other general maladies as hip dysplasia (canine), which are common across many types of dog breeds.
Mitral valve disease
Nearly all Cavaliers eventually suffer from disease of the mitral valve, with heart murmurs which may progressively worsen, leading to heart failure. This condition is polygenic (affected by multiple genes), and therefore all lines of Cavaliers worldwide are susceptible. It is the leading cause of death in the breed. A survey by The Kennel Club of the United Kingdom showed that 42.8% of Cavalier deaths are cardiac related. The next most common causes are cancer (12.3%) and old age (12.2%). The condition can begin to emerge at an early age and statistically may be expected to be present in more than half of all Cavalier King Charles Spaniels by age 5. It is rare for a 10-year-old Cavalier not to have a heart murmur. While heart disease is common in dogs generally – one in 10 of all dogs will eventually have heart problems – mitral valve disease is generally (as in humans) a disease of old age. The "hinge" on the heart's mitral valve loosens and can gradually deteriorate, along with the valve's flaps, causing a heart murmur (as blood seeps through the valve between heartbeats) then congestive heart failure. The Cavalier is particularly susceptible to early-onset heart disease, which may be evident in dogs as young as one or two years of age. Veterinary geneticists and cardiologists have developed breeding guidelines to eliminate early-onset mitral valve disease in the breed, but it is unclear if a statistically significant number of breeders follow these guidelines. The chairperson of the UK CKCS Club has said that "There are many members who are still not prepared to health check their breeding stock, and of those who do, it would appear that many would not hesitate to breed from affected animals." The MVD breeding protocol recommends that parents should be at least 2.5 years old and heart clear, and their parents (i.e., the puppy's grandparents) should be heart clear until age 5.
Syringomyelia (SM) is a condition affecting the brain and spine, causing symptoms ranging from mild discomfort to severe pain and partial paralysis. It is caused by a malformation in the lower back of the skull which reduces the space available to the brain, compressing it and often forcing it out (herniating it) through the opening into the spinal cord. This blocks the flow of cerebral spinal fluid (CSF) around the brain and spine and increases the fluid's pressure, creating turbulence which in turn is believed to create fluid pockets or syrinxes (hence the term syringomyelia), in the spinal cord. Syringomyelia is rare in most breeds but has become widespread in the Cavalier King Charles Spaniel, with international research samples in the past few years consistently showing over 90% of cavaliers have the malformation, and that between 30–70% have syrinxes. However, most dogs with syrinxes are not symptomatic. Although symptoms of syringomyelia can present at any age, they typically appear between six months and four years of age in 85% of symptomatic dogs, according to Clare Rusbridge, a research scientist. 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 ("air scratching"). The scratching behavior appears involuntary and the dog frequently scratches while walking – without stopping – in a way that is very atypical of normal scratching ("bunny hopping"). Scratching typical of SM is usually worse when the dog is wearing a collar, is being walked on leash or is excited, and first thing in the morning or at night.Not all dogs with SM show scratching behavior. Not all dogs who show scratching behavior appear to suffer pain, though several leading researchers, including Dr Clare Rusbridge in the UK and Drs Curtis Dewey and Dominic Marino in the US, believe scratching in SM cavaliers is a sign of pain and discomfort and of existing neurological damage to the Posterior horn of spinal cord region of the spine. If onset is at an early age, a first sign may be scratching and/or 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. Progression is variable though the majority of dogs showing symptoms by age four tend to see progression of the condition.A veterinarian will rule out basic causes of scratching or discomfort such as ear mites, fleas, and allergies, and then, primary secretory otitis media (PSOM – glue ear), as well as spinal or limb injuries, before assuming that a Cavalier has SM. PSOM can present similar symptoms but is much easier and cheaper to treat. Episodic Falling Syndrome can also present similar symptoms. An MRI scan is normally done to confirm diagnosis of SM (and also will reveal PSOM). If a veterinarian suspects SM he or she will recommend an MRI scan. Neurologists give scanned dogs a signed certificate noting its grade.
Episodic Falling (EF)
Episodic Falling causes "exercise-induced paroxysmal hypertonicity" meaning that there is increased muscle tone in the dog and the muscles cannot relax. Previously thought to be a muscular disorder, it is now known to be neurological; recently it has been discovered to be caused by a single recessive gene and a genetic test is available. Except for severe cases, episodes will be in response to exercise, excitement or similar exertions. Although EF is often misdiagnosed as epilepsy, which typically results in loss of consciousness, the dog remains conscious throughout the episode. Severity of symptoms can range from mild, occasional falling to freezing to seizure-like episodes lasting hours. Episodes can become more or less severe as the dog gets older and there is no standard pattern to the attacks. The onset of symptoms usually occurs before five months but can appear at any age. It is similar to Scotty Cramp, a genetic disorder in Scottish Terriers. About 1% of Cavaliers are affected by the condition, with 19% being carriers. Dogs with whole coloured coats were more likely to be affected than dogs with parti-coloured coats.
Thrombocytopenia and macrothrombocytopenia
As many as half of all Cavalier King Charles Spaniels may have a congenital blood disorder called idiopathic asymptomatic thrombocytopenia, an abnormally low number of platelets in the blood, according to recent studies in Denmark and the United States. Platelets or thrombocytes, are disk-shaped blood elements which aid in blood clotting. Excessively low numbers are the most common cause of bleeding disorders in dogs. The platelets in the blood of many Cavalier King Charles Spaniels are a combination of those of normal size for dogs and others that are abnormally oversized or macrothrombocytes. Macrothrombocytosis also is a congenital abnormality found in at least a third of CKCSs. These large platelets function normally, and the typical Cavalier does not appear to experience any health problems due to either the size or fewer numbers of its platelets.
Hip and knee disorders
Hip dysplasia (canine) (HD) is a common genetic disease that affects Cavalier King Charles Spaniels. It is never present at birth and develops with age. Hip dysplasia is diagnosed by X-rays, but it is not usually evident in X-rays of Cavaliers until they mature. Even in adult spaniels with severe HD, X-rays may not always indicate the disease. In a series of evaluations by the Orthopedic Foundation for Animals, the Cavalier was ranked 78th worst out of 157 breeds. The worst affected breeds were the Bulldog, Pug and Dogue de Bordeaux.Cavaliers can be subject to a genetic defect of the femur and knee called luxating patella. This condition is most often observed when a puppy is 4 to 6 months old. In the most serious cases, surgery may be indicated. The grading system for the patella runs from 1 (a tight knee), to 4 (a knee so loose that its cap is easily displaced). If a cavalier has a grade 1–2, physical rehabilitation therapy and exercise may reduce the grading and potentially avoid surgery. The grades 3–4 are most severe where surgery will most likely be needed to correct the problem to avoid the development of arthritis and lameness in the limb.
A disorder commonly found in Cavaliers is keratoconjunctivitis sicca, colloquially known as "dry eye". The usual cause of this condition is an Autoimmune diseases reaction against the dog's lacrimal gland (tear gland), reducing the production of tears. According to the Canine Inherited Disorders Database, the condition requires continual treatment and if untreated may result in partial or total blindness. This disorder can decrease or heal over time.A 1999 study of Cavaliers conducted by the Canine Eye Registration Foundation showed that an average of 30% of all Cavalier King Charles Spaniels evaluated had eye problems. They include hereditary cataracts, Corneal dystrophies in dogs, distichiasis, entropion, microphthalmia, progressive retinal atrophy, and retinal dysplasia.
Primary Secretory Otitis Media (PSOM), also known as glue ear, consists of a highly viscous mucus plug which fills the dog's middle ear and may cause the tympanic membrane to bulge. PSOM has been reported almost exclusively in Cavaliers, and it may affect over half of them. Because the pain and other sensations in the head and neck areas, resulting from PSOM, are similar to some symptoms caused by syringomyelia (SM), some examining veterinarians have mis-diagnosed SM in Cavaliers which actually have PSOM and not SM.Cavalier King Charles Spaniels may be predisposed to a form of congenital deafness, which is present at birth, due to a lack of formation or early degeneration of receptors in the inner ear, although this is relatively rare. In addition, more recent studies have found Cavaliers that develop a progressive hearing loss, which usually begins during puppyhood and progresses until the dog is completely deaf, usually between the ages of three and five years. The progressive nature of this form of deafness in Cavaliers is believed to be caused by degeneration of the hearing nerve rather than the lack of formation or early degeneration of the inner ear receptors.