My mother's cavalier, from an excellent breeder, has had perfect health all her life. At age 8, she has recently been diagnosed with a very light heart murmur -- so this is quite good; some dogs of any breed would have a murmur by this age (this is a breeder who follows the MVD protocols carefully and has dogs reaching 12-14 years).
I know of no people with dogs with early onset MVD from breeders *who follow the MVD protocol* (NB!! Many otherwise reputable and some very well known show breeders DO NOT! You need to ask for the heart clearance certs and they need to come from a cardiologist, NOT a vet!). I know of some who have had heart failure before age 10.
I know of many with dogs with SM from reputable breeders. If the research figures are correct (and they have been generally consistent across several studies in several countries) the rate is extremely high in cavaliers though the rate of symptomatic or probably more likely, noticeably symptomatic SM is low (I think many symptomatic dogs go undiagnosed because people think they have itchy ears or allergies, even though no source for these things is ever found). As this is a condition that has only been recognised as a major issue within the past decade, until recently there were few suggested guidelines for breeders. Also, many -- I would say the vast majority -- of breeders and clubs have vigorously refused to believe the rate of affectedness is anything like what researchers have been saying. Now -- as even breed club sponsored research in the US showed some very high rates -- this is becoming a more publicly recognised concern. There are also breeding guidelines which have been endorsed by the majority of the leading researchers in the area. But following them requires MRIing breeding stock which remains an expensive test and one most breeders right now are unwilling to pay for or cannot find in their region (there are growing numbers of low cost clinics though especially in the UK, which has very low cost screening clinics). Of those who do screen, many breeders are not disclosing their results either. Others feel they wish to wait to MRI til more is known about the condition, though my own feeling is that while people wait, they are very likely further diluting what few remaining good lines may be out there -- something that has been upheld so far by some initial statistical work which suggests almost all the good lines have died out or been undercut by breeding with more risky lines for SM (see discussion on the CKCS-SM Yahoo discussion group). The reality is that it is *extremely difficult* to find breeders in the US or UK or Ireland or Australia or anywhere else following the SM breeding guidelines (even though early results are very positive, see the research section at my site
www.smcavalier.com). I talk to many breeders in the US who do scan but are having a very difficult time finding any other breeder with screened studs, for example, even though reearchers have said screening studs is probably the most crucial group to do because they have a vastly greater influence on the genetic makeup of the breed as one stud can father thousands of puppies whereas a dam might give her DNA/genes to only 4-20 puppies. I do have a contact point for people in the UK looking for breeders who have litters from screened parents so anyone interested may contact me privately. Unfortunately I still do not have a reliable point of reference for breeders screening in the US though I can refer people to some who might have some suggestions. I have two dogs from one of the better known Irish breeders and one has SM and one is clear. I have a second rescue cavalier who almost certainly has SM (clinical diagnosis on symtpoms but not MRId, the boys have been MRId). But other than the SM, which does not overly bother either dog, mine have not had a single other health problem.
Knees, eyes and hips -- you can ask a breeder if they test for these. Some will say they rely on whether they know there are problems in their lines and don't test but I side with the breeders who say testing is important -- for example they have seen poor hip scores in dogs outwardly fine -- and as most pet owners will never report back any problems making it hard to assume they have no problems in their lines just on anecdotal evidence (pet owners should ALWAYS inform their breeder of halth problems to help improve their breeding programme!). Almost every single case I have heard of where dogs have problem hips, eyes or especially, knees -- the dog came from internet breeders, backyard breeders, puppy mills, pet shops -- not show breeders properly testing for these problems. I personally am unaware of any patella issues from good breeders who definitely test for this. It is however always possible to produce a puppy that has problems -- testing helps one greaty reduce problems, but not fully eliminate problems, especially those tht are likely polygenetic, like MVD and SM, meaning they can never be fully eradicated now as they are too widespread. They will always be a risk factor in any puppy.
This is why I strongly support looking for active *show breeders* who test, not the many charlatan breeders who claim they test on their websites but actually do not and often have forged certs as well, register with the bogus registries, and so on. It is very, very important to do your research on any breeder and if they are not actively showing -- eg if their dogs are not under regular, expert scrutiny -- I would not even consider buying a puppy from that person. I have yet to find ANYONE who truly breeds for health that produces puppies just for the pet market. Most of these simply have their vet listen to their dog's hearts once a year and this is the extent of their'testing' -- even though vets miss the majority of early onset murmurs, so vet heart testing breeding stock is virtually meaningless as far as MVD protocols go.
