The majority of problems seen in the Cavalier are common to toy dogs in general. Among the most common problems are early-onset heart murmurs, eye problems such as retinal dysplasia and cataracts, and luxating patellas (slipping knees). A small percentage of cavaliers will also develop orthopedic problems such as hip dysplasia, but since they are a small dog, it is not the catastrophe that it would be in a larger breed.  About 2% of all dogs, all breeds, will develop epilepsy.  A newly-recognized problem in toy dogs is syringomyelia or caudal occipital malformation syndrome, a crowding of the back portion of the brain that can lead to spinal problems.  Reputable breeders attempt to breed from stock free of major health defects, in hopes that their progeny will have a better chance at a healthy life. Puppies purchased from pet shops seem to have more problems than puppies purchased from reputable breeders.  Cavaliers should benefit from evaluations by veterinary specialists such as cardiologists, ophthalmologists, neurologists and reproductive specialists in an ongoing effort to improve the overall health of the cavalier.


Mitral Valve Disease:


The Achilles heel of the cavalier is Mitral Valve Disease.  The mitral valve problem is caused by endocardiosis, polysaccharide deposits in the valve leaflets.  Although these deposits are common in toy dogs, the problem seems to present earlier in the cavalier than some of the other toy breeds.  The deposits distort the valve, allowing it to leak, and some cavaliers in their golden years require heart medication to help them cope with the extra workload on the heart.  A rule of thumb is that 50% of cavaliers will develop at least a very mild heart murmur by the age of five or six, and over 90% will have a murmur by the age of ten. Cavaliers can still lead perfectly normal lives for years after developing the murmur, and many are never affected at all by the disease. If they are affected, it is usually very late in life and can be treated to some degree with medication. The main thing to keep in mind when looking for a pet for yourself, is that this problem must be tested for by breeders, and that any breeder that says they do not have this problem in their bloodline is either not telling you the truth, or is not educated in the disease. Mitral Valve Disease is in ALL bloodlines of Cavaliers, but with proper testing and knowledge on genetic inheritance, breeders can produce very healthy dogs that live normal lives. Much progress has been made in the last two decades to prolong the life span of the Cavalier. Cavalier breeders should use the information from the evaluation of cardiologists to help to make breeding decisions in hopes of delaying the onset of endocardiosis in future generations.  For those cavaliers that do develop mitral valve disease, careful monitoring and medical intervention often allows them to lead normal lives for many years.


 Eye Problems:


While debilitating eye problems are not common, breeders usually have their Cavaliers seen by board-certified veterinary ophthalmologists on a regular basis to screen for the possibility of hereditary eye disease such as retinal dysplasia, detachment, and cataracts.  Breeders occasionally come up with eye problems but are usually careful not to use Cavaliers with debilitating eye defects in breeding programs.


 Orthopedic Problems:


Because their bones are small, many toy breeds are sometimes troubled by luxating patellas. This simply means that the anatomy of a toy breed dog occasionally allows the knee cap to slip out of its groove in which it normally rides. While luxating patellas do not often hinder the dog’s movement, it is not uncommon for toy dogs to receive surgical correction of the problem. The other orthopedic problem that occurs in a small percentage of Cavaliers is hip dysplasia. This is a condition where the hip sockets are too shallow for the head of the leg bone. Although Cavaliers are usually not troubled by this condition because of their small size, bone deformity can cause pain in severe cases.  Breeders usually evaluate breeding stock for orthopedic problems and use that information to make breeding decisions that will hopefully minimize orthopedic problems.


 Syringomyelia or SM:


A newly-recognized and perplexing problem for cavalier breeders around the world is that of syringomyelia (SM), sometimes called syringohydromyelia, or caudal occipital malformation syndrome (COMS). This condition is similar to one found in humans called Arnold-Chiari malformation. In layman’s terms, the bottom half of the skull develops in such a way as to crowd the cerebellum of the brain, impeding the path of cerebrospinal fluid movement around the brain and spinal cord. The increased pressure and pooling of cerebrospinal fluid may cause irritation and damage to the spinal cord, resulting in symptoms of neck scratching, headache, and in rare cases, paralysis. Rattlebridge, in cooperation with The Ohio State University College of Veterinary Medicine, had taken a leading role in the research of this international breed crisis. Before the neurological department at OSU was sidelined due to the departure of the neurological medical staff, the ongoing study was earmarked to follow our extended family of dogs which was done on al limited basis before the Veterinary neurosurgeon and neurologist left for other opportunities. Despite claims to the otherwise, it is felt that no line is safe from syringomyelia. Unless and until the gene marker(s) for this disease are identified, toy dogs will continue to be affected. Rattlebridge is committed to assisting in both research of the disease and education of cavalier breeders. At the 2004 ACKSC specialty, Meredith presented an educational seminar to cavalier breeders from across the nation. It is hoped that cavalier breeders will be honest in sharing their knowledge of affected dogs. As Dr. George Padgett, authority on canine genetic disease, has said, "We need to quit whispering about defects, and gossiping about defects, and instead set up a sound program that allows the standard selection procedures to go on so that we breed good dogs and avoid major defects." While only a small percentage of cavaliers ever develop symptoms of SM, many dogs have the disease and remain asymptomatic. The most definitive tool for the diagnosis of SM is by MIR scan. Hopefully, as breeders take advantage of the MRI procedure for their breeding stock, we may be able to have a better grasp of the disease; however, in talking with respected breeders the world over, we have found that most believe that we will not eradicate the disease until we find a gene marker.


 Flycatcher's Syndrome:


Occasionally a Cavalier will experience a disorder called Flycatcher’s Syndrome in which the Cavalier repetitively bites or snaps at the air around his head trying to get a fly. Flycatchers is thought to be a form of epilepsy and may also be a compulsive-obsessive disorder. It may be seen more frequently in the Cavalier than in other breeds.  If the condition is severe, medical intervention may be warranted.

 Low Platelet Count in the Cavalier King Charles Spaniel—not a problem:

Cavaliers sometimes have a lower platelet count in their blood count which worries some veterinarians who do not know that this is normal in a Cavalier. Cavaliers may have a lower platelet count, but they also have larger platelets. The platelets must be hand counted to get an accurate reading. Dr. Kim Hamer from Atlanta, Georgia, is doing a study on the platelet count in Cavaliers which is outlined below.  We are only including mention of the low platelet count of some Cavaliers so Cavalier owners reading this will be informed just in case they have a Cavalier with a low platelet count being misdiagnosed by a veterinarian who is not familiar with our breed.


 Copyright 2004 by Meredith Johnson-Snyder

Rattlebridge Cavalier King Charles Spaniels  


 Asymptomatic thrombocytopenia and Macrothrombocytosis

in the Cavalier King Charles Spaniel—study by Dr. Kim Hamer DVM from Atlanta, Georgia

“Platelets are also called thrombocytes. These are the blood cells that are responsible for normal blood clotting.  Thrombocytopenia is an abnormally low blood platelet count. . Macrothrombocytes are abnormally large blood platelets.  

Normal blood platelet counts should be between 150-200,000. Dogs will have bleeding abnormalities if their counts are below 40,000. However, the Cavalier King Charles Spaniel (CKCS) may have counts well below 40,000 with no problems. Approximately 30% of CKCS have macrothrombocytosis and/or thrombocytopenia. This appears to be a congenital abnormality. The CKCS does not experience any health problems despite these changes. It is thought that the large platelets of the Cavalier are able to provide the same function in lower numbers than that of other breeds. Because CKCS platelets are so large, automated cell counters may mistakenly count them as white blood cells, artificially lowering the platelet count. Additionally, these cells may not be recognized when examined under the microscope on a blood smear because they may not look like the platelets of other breeds.”   Remember, the CKCS does not appear to experience any health problems due to this condition, which has only been reported in our breed and no others!  


Copyright 2004 Dr. Kim Hamer DVM