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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
www.rattlebridge.com
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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 |