what does asymptomatic mean? .. that's not as good as 'clear'?
what does asymptomatic mean? .. that's not as good as 'clear'?
Asymptomatic means that the dog doesn't have symptoms. There is no "clear" scan - there are scans with grades (A or 0) and breeding guidelines. Parents graded "A" or "0" do not guarantee you that your dog will not have SM.
I would recommend that you research this subject more. Even on this forum there is entire section on SM.
I also would recommend to focus on heart testing and current status of the parents and ancestors as MVD is what is found more often in our breed.
Greetings from Joanna & Maxi, Zoe & Arabella (Kissabella)
I have done some more research and found this about heart murmurs in dogs
"There are many different types of murmurs, and causes for them. Some can be repaired surgically, some controlled by medication, some that disappear, and some that cannot be treated"
What type of heart murmur do Cavaliers get generally? If the breeder knows a dog has heart murmur before selling it to you, surely they know which type and whether it needs surgery or just medication, or that it might disappear? If it needs surgery shouldn't the breeders sort that before trying sell the puppy? ..or do they rehome those one's free to anyone willing to pay for the puppies surgery and risk that it may not survive the op?
I know there are some cases where some people find out later in the dogs life that it has an heart murmur and it's probably had it for years and they never knew, so I relaise they can also be very mild and missed unless a dog happens to need treatment for something else.
I also heard that what grade the vets give them to some extent depends on who well they can detect the heart when it was examined, (could it be missed in a very wriggly puppy?)
Is there an age whereby if they had an heart murmur it would have been diagnosed as to how serious it was and how much exercise they could cope with , if you were looking to adopt an older dog?
As Joanna said earlier, the main type of murmur that Cavaliers are prone to is MVD - mitral valve disease. It can be controlled by medication, but some dogs don't respond well to the treatment. I have a ten year old here who actually has only a Grade 3/4 murmur, but she went in to CHF two years ago and started her meds then. To which, luckily, she responds very well - although in very hot weather they do need tweaking a bit. She was diagnosed by my vet, but I took her to a club heart testing day for a thorough check by the cardiologist who was doing a low cost clinic arranged by my regional Cavalier Club. All Clubs offer their members this opportunity.
Breeders do tend to have their dogs checked (preferably by a cardiologist) annually for murmur sounds, and there is a code of best practice - grandparents clear at five years of age, dogs not to be bred from until - it used to be two years of age, but now with MRI scanning at 2.5 it's gone up.
What individual breeders do in relation to selling their dogs is very much a matter for discussion and arrangement between themselves and who they might be letting a dog go to. Very often an early murmur in a dog has no deleterious effect - the only time I've had a pup with a heart murmur I let her go to a home which had other dogs of mine for free. This was years ago, and she's still alive I'm pleased to say. On the other hand, some dogs develop a murmur late in life which progresses very rapidly.
If you are looking to adopt an older dog, again the best thing to do is to discuss the heart status with the breeder or rescue centre.
There is a form of murmur found in some puppies, which may be expected to disappear as the dog matures. But the murmurs which are problematic for cavaliers are, primarily the sounds coming from a defective mitral valve (MVD), and secondarily the sound coming from a defective tricuspid valve. Statistically, nearly all CKCSs will develop MVD, and over half of them will do so by their fifth birthday.
MVD is almost always progressive, meaning it keeps getting worse. But rarely does a mitral valve murmur start before the age puppies usually are sold by their breeders. MVD is genetic in the breed, so while breeders most likely would not know that their puppies definitely will develop murmurs, they should realize that their puppies inherit the disease from their ancestors. There is a breeding protocol recommended by heart specialists and geneticists, which is designed to eliminate early-onset (meaning, a murmur starting before age 5 years) MVD in future generations of cavaliers. However, most CKCS breeders refuse to follow it because it is inconvenient for them.
Treatment of MVD is mainly by medications to try to manage the progression of the disease and ease the symptoms. There is a webpage which discusses MVD in the cavalier in some detail at http://cavalierhealth.org/mitral_valve_disease.htm
It is fair that say that most dogs, pedigree or mongrel, are prone to MVD later in life. The problem with Cavaliers is the early onset, but it is variable.
I live in France and most breeders; and certainly all who are signed to the “charte de qualité”, have ultrasound tests done on their dogs every 18 months, and the photos are checked by one of six appointed veterinary cardiologists to determine the grade. There are, in France, five grades from strictly normal to grade four. Often dogs at grades 1 and 2 do NOT have audible murmurs, so the disease is detected earlier than if just auscultation was carried out. There is quite a strict protocol, but a three year old dog at grade 1 may be bred from. Under another scheme he or she would not have an audible murmur. It does seem rather daft that a dog who was grade two at age 7 could be bred from but if he went to grade three at age 9 he could no longer be used! I have a seven year old dog who is grade 2 but there is only a faint “click” on auscultation: he’d probably be classed clear under another scheme.
MVD is polygenic; there is no clear mode of inheritance. There also seem to be several different patterns: dogs who develop a murmur at a young age and then it progresses very slowly, while others can be clear until a good age and then develop MVD which progresses fast.
Others develop it late and it still progresses slowly. I currently have two bitches who were born on 4 September 2000 and whose father, clear when they were born, developed MVD at age 6 and died within a year. They have both been on (different) medication for the last couple of years; so were 11 or 12 when they started, but show no clinical signs of the disease. One is a bit arthritic. Their father’s early death is, I think, fairly exceptional, and they clearly didn’t inherit that particular set of genes.
A very good guideline is to find out the ages that dogs in the ancestry of a puppy lived to: if plenty lived to a good age, it is reasonable to hope they all will. However, as with humans, nothing can be guaranteed!