Mitral Valve Disease Breeding Protocol
for the Cavalier King Charles Spaniel

• The MVD Protocol
• In Depth
• -- history of the protocol
• -- since the 1998 symposium
• -- Cavalier breeders' objections
• Related Links

Early-onset mitral valve disease has been found to be "highly heritable" in the Cavalier King Charles spaniel breed, and "selection against the disease should be successful.", according to an April 2010 research report.

Veterinary specialists have designed breeding guidelines to eliminate early-onset mitral valve disease in Cavalier King Charles spaniels. The guidelines (called the MVD Breeding Protocol) were strongly advised in 1998 by a group of veterinary cardiologists and a geneticist who had dedicated years of study to mitral valve disease in Cavaliers.

Since 1998, only an insignificant minority of breeders of Cavalier King Charles spaniels in the United States have followed these guidelines. In the ten years since then, the vast majority of such breeders have squandered at least three generations (at 2.5 years per generation) of Cavaliers towards eliminating early-onset (onset before age 5 years) mitral valve disease. By shunning the MVD Protocol and actually increasing the breedings of Cavaliers in violation of the MVD Protocol, the great majority of American breeders have acted irresponsibly and in callous disregard for the health and welfare of future generations of Cavaliers.

In Depth

-- History of the protocol

The MVD Breeding Protocol has been designed to eliminate early-onset mitral valve disease. Veterinary cardiologists throughout North America and Europe conducted studies of MVD in Cavaliers in the 1990s.

A group of four world renowned veterinary cardiologists, Doctors Andrew Beardow from England, James Buchanan from the United States, Virginia Luis Fuentes from Scotland, and Bruce Keene from the US, and an internationally respected geneticist, Professor Lennart Swenson from Sweden, each presented reports on the results of their professional studies about the disease in1998. Their conclusions:

• MVD is the leading cause of death in Cavaliers;

• It is a hereditary, genetic disorder;

• There has been no statistical improvement in Cavaliers' mitral valves in the eleven years since the first studies; and

• The disease can be decreased and the age of onset delayed by following guidelines of only breeding Cavaliers who are over the age of 2.5 years, have hearts free from MVD murmurs, and have parents whose hearts were MVD murmur-free at age 5 years. No Cavaliers should be bred which have murmurs before age 5 years.

These experts presented their findings and conclusions at a symposium in May 1998, which was sponsored by the Cavalier King Charles Spaniel Club, U.S.A. (CKCSC,USA). Under the leadership of its then president, C. Anne Eckersley-Robins, the board of directors of the CKCSC,USA then also endorsed the MVD Breeding Protocol in 1998.

These guidelines were developed by the Swedish Kennel Club, and are based upon that club's successful efforts to reduce hip dysplasia in Rottweilers. Between 1976 and 1994, the percentage of Rottweilers diagnosed with hip dysplasia decreased from 36% to 11% by following a similar breeding program. Professor Swenson reported that hip dysplasia is a multifactorial, polygenic trait, and it is believed MVD is also.

He pointed out that it is not realistic to expect to eliminate the causes of mitral valve disease by any breeding program without further research into the reason for the high prevalence of the disorder in Cavaliers. Instead, the goal is to postpone the onset of the disease so that all Cavaliers die a natural death before MVD becomes a health problem.

Professor Swenson believes that if the recommended breeding guidelines are followed by all breeders, we would see improvement after the first generation and significant progress towards delaying the onset of MVD over two to three generations. Mitral valve disease is not controlled by a single gene, but there may be one dominant gene which controls the worst (earliest onset) 30% of MVD cases. He stated that if that is correct, this worst gene would be the first one to disappear once the breeding guidelines are universally followed.

Dr. Luis Fuentes reported on the British studies, which began in 1987 and showed that 50% of all 5 year old Cavaliers had MVD murmurs, and all examined Cavaliers over the age of 10 had murmurs. The English Cavalier King Charles Spaniel Club has endorsed the Swedish guidelines, and it also is publishing a registry of all Cavaliers over age 5 years with murmur-free hearts.

Dr. Beardow explained that the guidelines call for each breeding Cavalier to be examined annually by a veterinary cardiologist using a stethoscope. He said that, compared to an echocardiographic examination, the use of a stethoscope (called auscultation) by a cardiologist is 90% accurate in detecting MVD. In view of the relative wide availability and low cost of auscultation diagnosis, it is preferred over more expensive alternatives. Compliance with the guidelines is enhanced by using relatively inexpensive, simple, and effective measuring methods. Also, the speakers expressed their concern that the testing device be specific enough to identify MVD but not so sensitive as to eliminate all of the breeding stock.

Most importantly, the experts emphasized that, to be effective, the breeding guidelines must be widely supported and uniformly implemented. The biggest reason that breeding guidelines fail is that the breeders do not follow them. Therefore, the results of the tests should be published for all to see. The English Cavalier Club's registry of murmur-free dogs is aimed at encouraging breeders to follow the guidelines.

A printable abridged version of the transcript of the May 1998 MVD symposium proceedings is available online, or send your name and postal (street and street number) mailing address to Editor@CavalierHealth.org for a full verbatim transcript to be mailed to you.

-- Since the 1998 symposium

Since the 1998 report, studies conducted by veterinary heart and genetic specialists have confirmed the efficacy of the MVD Breeding Protocol. In a 2000 research study of 4,255 CKCS heart examinations, Dr. James Wood of the Animal Health Trust in the United Kingdom reported that:

• MVD is the major killer of Cavaliers under 10 years of age.

• Veterinary cardiologists were better able to identify early mitral valve murmurs than were non-specialist veterinarians.

• The parent's heart status can predict the offspring's future heart status.

• The offspring were ten to twenty times more likely to be free of MVD murmurs if the sire's heart was clear of murmurs at ages nine to eleven years.

In a 2009 report by UK veterinary cardiologist Simon Swift to the UK's Cavalier Club, he stated that 50% of Cavaliers still are developing MVD murmurs by their fifth birthday. This is because most breeders are not following the MVD breeding protocol.

-- Cavalier breeders' objections

Since 1998, only an insignificant minority of breeders of Cavalier King Charles spaniels in the United States have followed these guidelines. In the twelve years since then, the vast majority of such breeders have squandered at least three generations (at 2.5 years per generation) of Cavaliers towards eliminating early-onset (onset before age 5 years) mitral valve disease.

We now find some Cavalier breeders who claim to be following a MVD breeding protocol which turns out not to be the MVD Breeding Protocol. Some breeders have made up their own watered-down breeding protocol (something like: "try to breed" females over 2 years of age and MVD-clear, to males over 6 years and MVD-clear), which makes breeding decisions much easier for them, but which totally ignores the many years of statistical research and cardiologists' and geneticists' recommendations which has led to the MVD Breeding Protocol.

The American Cavalier King Charles Spaniel Club (ACKCSC), which is the CKCS parent club of the American Kennel Club (AKC) has pointedly ignored the MVD breeding protocol and has gone so far as to even concoct a fictitious MVD breeding guideline of its own. On its website (as of this writing in 2010), the ACKCSC has stated:

"Currently, the recommended practice is to wait until a Cavalier is two years old or older before the first breeding and to know the parents and ancestral cardiac status. Cavaliers with early onset presentations of MVD (before four years of age) should not be bred and breeders need to work with the guidance of their cardiologists."

Instead of not breeding until age 2.5 years, ACKCSC claims in its baseless "recommended practice" to start breeding at 24 months, and it also shortens the definition of early-onset MVD from five years to four years. Instead of requiring that all four parents of the breeding pair be certified to be murmur-free by age five years, ACKCSC says its "recommended practice" is simply "to know the parents and ancestral cardiac status." That is a meaningless phrase apparently designed to provide AKC breeders with "cover" for ignoring the real MVD breeding protocol. It allows them to claim that, in their "wisdom" as experienced breeders, they "know the parents" and they have taken into account the "ancestral cardiac status".

The ACKCSC, as the AKC's parent club for Cavaliers, has been assigned by AKC the responsibility of "the education of breed owners on the nuances of the breed, and overseeing the breed's health and welfare." So, the ACKCSC is the primary source for AKC breeders to find out about the health of Cavaliers. The ACKCSC has refused to accept that responsibility, and instead, it has misled the AKC breeders about the true MVD breeding protocol in the United States.

By shunning the real MVD Protocol and actually increasing the breedings of Cavalier King Charles spaniels in violation of the MVD Protocol, the large majority of American breeders have acted in callous disregard for the health and welfare of future generations of Cavaliers. They continue to breed untested, un-cleared, and/or under-aged Cavalier King Charles spaniels in the United States, and the number of breedings and resulting litters of these early death-marked Cavaliers has increased dramatically since the American breeders were warned by the experts in 1998 to stop breeding underaged Cavaliers and never breed any Cavalier in violation of the MVD Protocol.

Similarly, in the United Kingdom, the chairman of its Cavalier King Charles Spaniel Club stated in March 2009:

"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."

Related Links

Mitral Valve Disease
Questions for Breeders
Board Certified Veterinary Cardiologists

An MVD support group is http://uk.groups.yahoo.com/group/mvdincavaliers

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