by Dr. John V. Ioia, MD, PhD

Reprinted from the AKC Gazette Magazine, June 2024

I host a local radio program.  One of my jobs is to read a disclaimer at the start of each show that states the opinions expressed are those of the host(s) and do not represent the organization, its sponsors or the channel.  Similarly, the following article represents my opinions.   As a physician and one with 50 years’ experience in AKC activities plus 20 years’ involvement in the Cavalier King Charles Spaniel, including have bred and shown multiple champions and having Cavaliers live healthy lives into 16 and 17 years, I may have learned a few things.

The dog world was recently shocked by a Norwegian Court’s decision barring the breeding of CKCS based on what the judges claimed was their health.  While we could start by blaming the court for a biased opinion, it has been my opinion that the Norwegian Cavalier breeders put up a poor defense.  Perhaps there were mitigating circumstances for their actions but I believe that American Cavalier breeders could, would and should create a knowledgeable dialogue based on the improvement in health and longevity of American CKCS in the last 30 years.

Advice regarding Health Testing may be found on the website. This includes Eyes, Hearts, SM, Hips, Patellae, PSOM, Curly Coat and Dry Eye.

Let’s start with the issue of MVD, degenerative or myxomatous mitral valve disease.  It is prevalent in the CKCS and it is presumed that its prevalence is due to early breeding, where the numbers of dogs was limited and the gene was “Locked-in.”   Yes, when I entered the breed, MVD seemed to be a scourge.  Perhaps I have just been lucky but in our 20 years in the breed we have had just two dogs requiring Pimobendan.  One passed at 17+ years.  He had a murmur but died of other old-age causes.  The second is 14 and not yet in failure.   Many other breeder-exhibitors report similar experiences with dogs living healthy lives into their teens.  Careful testing and breeding practices have led to better longevity.  An ACKCSC health survey could document the trend.  Longevity has been achieved by the empirical actions of breeders.  A genetic marker may be on the horizon, which may further aid breeders.  Incidentally, MVD does occur in other toy breeds but has not received the attention of the CKCS.  Health screening by an ACVIM Cardiologist is suggested at 2 years on breeding stock.

Syringomyelia or SM is another condition occurring in the CKCS.  SM is a disorder in which a cyst or bubble called a Syrinx forms within the spinal cord.  Pain is the most common clinical sign, often observed as phantom scratching to the affected side of the neck.  SM appears in many dog breeds, and particularly in a number of toy breeds.  SM in Cavaliers has been identified and well researched.  Along with CKCS, SM has been documented in English Toy Spaniels, Brussel Griffon, Yorkshire Terrier, Maltese, Chihuahua, Miniature Dachshund, Miniature and Toy Poodle, Bichon Frise, Pug, Shih Tzu, Pomeranian, Staffordshire Bull Terrier, Boston Terrier, Pekingese, Miniature Pinscher, and French Bulldogs.  Prevalence in other breeds has not been measured at this time.  MRI is the definitive exam in an affected individual and a mode of inheritance has not been established.

Some breeders have chosen to MRI all breeding specimens at 3-5 years.  This is expensive, requires anesthesia and since no mode of inheritance is established, may not be reasonable.  MRIs are graded A – D, with D being high grade or the worst.  There are no guarantees that breeding an A dog or bitch will produce an A puppy.  I ascribe to the school that a breeder should MRI a dog at risk and if positive, should neuter that animal and not use it for breeding.  Having lost a prized dog to anesthesia during an MRI, I have my reluctance to MRIs of all dogs.  My one experience with SM in a beautiful bitch is now being managed nicely with 100mg Neurontin daily and her symptoms seem weather or barometric pressure dependent.   Symptoms may wax and wane.

When discussing SM, one must also discuss Chiari Malformation.  Like the Arnold Chiari Syndrome in humans, CMs are structural changes that occurs where the skull and the upper end of the spinal cord meet.  The foramen magnum is the opening to the spinal canal at the bottom of the skull.  Normally, the cerebellum and parts of the brain stem sit in an indented space at the lower rear of the skull, above the foramen magnum.   When part of the cerebellum is located below the foramen magnum, it is called a Chiari malformation.  It will produce symptoms like SM and an MRI is diagnostic.  While surgery has been suggested, it is most often treated with medication; Neurontin, Steroids, NSAIDs and Proton Pump inhibitors.  Despite articles like “Pedigree Dogs Exposed,” it is not as widespread and I have not experienced it in our dogs.

Otitis media (middle ear infection) may affect the CKCS.  Due to the mucoid nature of this ear disease, the condition has been referred to as primary secretory otitis media (PSOM) or “glue ear.  Signs of PSOM may not be apparent.  When present, they may include hearing loss, facial paralysis, head tilt, involuntary eye movement, unsteady gait, neck scratching and head shaking, some of which are similar to SM.  There are no patterns of inheritance for PSOM and testing occurs only with concern for affected individuals.

Dry Eye and Curly Coat Syndrome is due to an autosomal recessive gene, a mutation of the FAM83H gene.  Puppies are born with an unusually rough, curly hair coat and do not produce tears, which leads to the early symptoms of corneal ulcers, infection, and ocular discharge.  If pups survive, you may also notice that their paw pads are especially thick and crusty (hyperkeratotic) and that their nails are malformed.  This may result in euthanasia.  Fortunately, it has been virtually eliminated by breeders and is easily tested for with a simple cheek swab.

Cavaliers do not generally suffer from any serious eye problems.  They rarely inherit juvenile cataracts, retinal dysplasia, or other eye problems like Corneal dystrophy, Distichiasis, Microphthalmia and Retinal dysplasia eye.  Breeders should screen their Cavaliers with board certified veterinarian ophthalmologists and only breed Cavaliers that are normal or comply with CERF breeder guidelines.  As of this writing, there are no known patterns of inheritance and there is no advice regarding breeding,

I have left the discussion of structural problems of hips and knees for last.  Hip Dysplasia is a congenital and degenerative condition.  It is a polygenic disease, meaning that there are several genes as well as environmental factors that produce the problem.  Certain larger breeds such as German Shepherds, Golden Retrievers and Labrador Retrievers have a predisposition for this condition though it can occur in all dogs, even smaller dogs as the Cavalier King Charles Spaniel.

Diagnosis of hip dysplasia is made by x-ray.  As this is a degenerative disease, breeding stock in dogs with a breed predisposition are x-rayed after the age of 2 for signs of the disease.  An affected dog should not be used for breeding.  In the Cavalier, it is a breeder’s choice to x ray for hip dysplasia as the incidences of the condition seems low. (per ACKCSC Website).  As with some inherited diseases, a negative x-ray may not answer the question of whether a dog is a carrier and can pass the condition to its offspring.

Patellar luxation also called slipped stifles is common to many breeds including Poodles, Yorkshire Terriers, Pomeranians, Pekingese, Chihuahuas, Miniature Pinschers and Boston Terriers and Cavaliers.  Females seem to be at higher risk for this condition.  Diagnosis is relatively simple and involves palpating the knee joint and manually luxating the patella.  Patellar luxation is classified in four grades depending on severity and is subjective.  Mild patellar luxation (grade 1-2) may be discovered as an incidental finding especially in a growing pup or a female in season.  Patellar luxation may also occur in any breed due to trauma.  Developmental patella luxation results from abnormalities in the bones of the rear legs, such as a shallow trochlear groove.  Cavaliers used for breeding should have normal patellas as determined by an OFA examination at age one. The patellas should be reevaluated as the Cavalier ages.

These are my opinions on health and health testing and I hope they generate some interesting discussion and some clarity.  For more information, go to the website.