Mitral Valve Disease Breeding Protocol - Cavalier King Charles Spaniel

Do not breed any CKCS before age 2.5 years.

Do not breed any Cavalier under the age of 5 years, unless its parents' hearts were free of MVD murmurs by age 5 years.

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.

They continue to breed untested, un-cleared, and/or under-aged CKCSs in the United States, and the number of breedings and resulting litters of these early death-marked Cavaliers has increased dramatically since those 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.

Related Links: Mitral Valve Disease

Questions for Breeders

Board Certified Veterinary Cardiologists

In Depth:

The vast majority of American breeders of Cavalier King Charles spaniels refuse to follow the MVD Breeding Protocol designed to eliminate early-onset mitral valve disease. A group of four world renowned veterinary cardiologists and an internationally respected geneticist conducted studies of MVD in Cavaliers in the 1990s. Doctors Andrew Beardow from England, James Buchanan from the United States, Virginia Luis Fuentes from Scotland, and Bruce Keene from the US, and Professor Lennart Swenson from Sweden, each presented reports on the results of their professional studies about the disease. Their conclusions:

(a) MVD is the leading cause of death in Cavaliers;

(b) It is a hereditary, genetic disorder;

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

(d) 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.

The 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.

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:

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

• 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.

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.

By shunning the real MVD Protocol and actually increasing the breedings of Cavalier King Charles spaniels in violation of the MVD Protocol, the vast 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.