Taking it to heart

Just over a week ago I received a dreaded email, one though that I knew would come eventually. The email was from Gill who has had two Cavapoos from us. She had her first one, Alfie from our first ever litter of Cavapoos. The email is as follows,

Hi Jane
I know after talking to you that you wanted to keep an eye on the health of your offspring. Alfie, 2009, Millie's first cavapoo litter, has been diagnosed as having a grade 1-2 heart murmur. i am not unduly concerned as he is fit and healthy and enjoys hunting rabbits.  I know that this is disappointing as you were hoping that they may be free of this cavalier problem. I will keep you updated if anything changes. Kym is fine and of course they both give me so much pleasure and are my best friends.
Best wishes
Gill

Firstly I thank Gill for letting me know about Alfie being diagnosed with a heart murmur and at this point I must admit a fault, that when I embarked on cross breeding, that I did not stress to everyone having a pup from me the importance of letting me have health updates, especially if diagnosed with a condition that has a high probability of being hereditary. At this time though this is my first report of a Cavapoo with a heart murmur and the probablity is high that it is Mitrial Valve Degeneration (MVD).
Alfie was born in the Spring of 2009, so is now around 5 1/2 years old.  Millie is his Mum and my sisters Poodle Rollo is his Dad. Millie was disgnosed with a grade 2 heart murmur at  4 years old and 11 months old. The only thing I can draw from this is that the onset of MVD is later than earlier in Alfie than his Mum. Millie at seven years old is still graded 2 for her heart murmur, so the onset is seeming to be slow.
This blog is going to look at this this condition and the realities of breeding out from a group of dogs that is so badly effected by this condition and what can really be expected from crossing this breed with the heart condition MVD. One of the big questions is, should I breed from dogs, knowing that they have a high probability to develop MVD ?
First lets try to understand what MVD is and I will try to keep it simple and to the point.

 Heart disease in dogs

Approximately 10% of  general dog population, around one out of every ten dogs will develop some form of heart disease, approximately though 80% of heart disease in the general dog population will be MVD. So that is every ten dogs out of hundred that get heart disease, eight of the ten dogs with heart disease will be diagnosed as MVD. MVD is more common in small dogs, than medium to large dogs.
MVD is the leading cause of death in Cavaliers all over the world. MVD is a polygenetic disease (depending on the simultaneous presence of several genes, they are not inherited as simply as are single gene disorders). Statistics have shown that MVD may afflict over 50% of Cavaliers by the age five and nearly all Cavaliers have MVD by the age of ten, if they live that long.

 What is the Mitrial Valve ?

The heart has four chambers. The upper chambers are the atria (atrium for one chamber) and the lower chambers are the ventricles. The heart is divided into left and right sides. Each chamber (atrium) of the heart has a one-way valve to keep blood from flowing back. The Mitrial Valve is between the left atrium and left ventricle.

Dogs heart cross sectioned showing the mitrial valve

What is MVD ?

MVD is a degeneration of the heart's mitrial valve. The mitrial valve is one of four sets of valves in the heart. As degeneration of the valve occurs, the valve does not close fush after each pump of the heart and blood thus backflows from the ventricle back into the atrium.
The function of the heart is to pump unoxygenated blood to the lungs to be oxygenated and to then pump that oxygenated blood to the rest of the body on a continuous loop. The unoxygenated blood returns to the heart by entering the right atrium (right upper chamber). It stops there briefly and is then pumped into the right ventricle (right lower chamber). From the right ventricle the blood is pumped into the lungs to pick up oxygen.
Once the blood is oxygenated it flows back into the left atrium (left upper chamber) and is held there before fowing into the left ventricle. From the left ventricle, the oxygenated blood is pumped throughout the body going through the aorta and the arteries.
The left ventricle is surrounded by the largest and strongest of the heart muscles and this large muscle is needed to keep blood pumped out of the heart and throughout the body.
The high pressure created when the left ventricle contracts and pumps blood out, means the mitrial valve has the greatest pressure on it of the four sets of heart valves.
With MVD, as the valve degenerates further, more and more blood backflows each time the heart pumps, causing the onset of congestive heart failure, when the heart struggles to pump blood to the rest of the body.
First symptoms of congestive heart failure are coughing more than usual (during or after exercise or a few hours before bedtime)
Having a hard time breathing or exercising and tiring easily.
Pacing before bedtime and having a hard time settling down.
As the valve degenerates further, symptoms develop as follows. A swollen belly from fluid buildup in the lungs and other organs
Fainting because of lack of blood flow to the brain. Change in the colour of the gums and tongue to bluish grey because of poor oxygen flow and weight loss as the dog loses the ability to store healthy fat.

Anterior view of the heart showing the heart valves

MVD in Cavaliers

In most dog breeds MVD is seen in old age between the age of ten to fifteen years old and often vets will call it a natural change of the heart because basically seen in old age, it is consistent more with natural wear and tear, known as ageing. When seen in old age, the onset is often slow. In Cavaliers MVD is seen at an alarmingly high rate before the age of ten, with on average over half Cavaliers have the onset of MVD by the age five and by ten, nearly all Cavaliers have a heart murmer. The earlier the onset, it seems the more rapid the onset (my theory on this is, that the younger the dog with MVD, the more active the dog is and thus the heart is under more stress, than an old dog that is less active with MVD onset), with onset to life threatening as little as one year to 3 years. In my experience if they have a MVD before they are four,  they will be lucky to see seven.
There is a Cavalier breeding protocol for Cavaliers for MVD which was devised by a group of world renowned veterinary cardiologists in 1998,  "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."

They believed that if this prtocol was followed to the word, that within a couple generations we would soon see an improvement in the age onset being seen for MVD and that onset could be steadly moved back towards old age in Cavaliers. If this protocol had been adopted wholesale  or even partly adopted by the Cavalier Clubs and Kennel Clubs around the world in 1998, I think the Cavalier would be in a lot better place now, but unfortunately it was not and the Kennel Club (KC) and the Cavalier Club in the UK still today, only recommend this protocol (unfortunately as history proves all to often, recommending something is about as effective as pissing into the wind, when it comes to dog breeding) and under the Kennel Club Assured Scheme that the KC so trumpet, heart examinations are still only a recommendation and you can buy a KC Assured Scheme bred Cavalier that has never ever had its parents hearts examined and they won't be breaking any Assured Scheme rules, because under the KC Assured Scheme, they don't have to examine breeding stock hearts. The cardiologist vet I use to examine my Cavaliers hearts told me that in the last twenty years, he has seen, "No improvement, in MVD in the general population of Cavaliers," and actually thinks the problem is worse.
You may ask why the KC don't make all breeders that register pups with them abide by the Assured Scheme rules and why they don't make it a rule with Cavaliers, that the parents must be heart checked to register pups with them ? The simple answer is they don't want a fall in the registery of pups, because how would they afford their swanky Clarges address in London or be able to afford the dog showing part of the outfit and you thought the KC abided by the quote on their website , "dedicated to protecting the welfare and promoting the health of all dogs", when it is obvious that when you scratch just below the surface, they are not protecting the welfare of Cavaliers or promoting the healthy breeding of Cavaliers.
 The KC have learnt a very good PR trick and that is look like you are doing a lot, but in fact you are not , give some money to charities, divert the eye from the real problems, it's the good shit, bad shit ratio, get it right and you will be surprised how much bad shit you can get away with. Nothing really has changed that much with the KC, number one concern is the aesthetics of a breed, the breed standard objectifies the dog and the functional dog is lost and replaced with a caricature that ribbons can be hung from. The KC though will use the old chestnut excuse, that if they get to tight on registery rules of pups, these breeders will go underground. My answer to that is, if the KC can assure us that all pups registered with them are bred to the highest standards, then we will know where the good breeders are and the ones not with them, are the ones to be weary of, but at the moment you are just as likely to buy a puppy farmed puppy that is KC registered as not registered with them, so their reasoning does not help but confuse the situation of where to find a good breeder.

Healthy mitrial valve

A myth about MVD aka bullshit

Before we go on , I just want to blow one myth I have heard, out of the water. Now as a breeder and as someone who is happy to help people with inquiries even if they are not getting a puppy from me, I get to hear the utter bullshit other breeders will spout, just to get a sale. The worst and most odious one I have heard is about cross breeding and MVD, and the myth goes, "apparently you don't have to worry about MVD in Cavapoos because when you cross them with the Poodle they won't get it, in fact they won't get any hereditary health issues, because apparently, the two breeds don't suffer with any similar conditions." I was asked if this was true, thankfully the person asking, thought it untrue and my answer started by me saying, "I'm sorry to be blunt, but that is utter bullshit." He replied by saying, "From my limited knowledge of genetics, I thought it the case."  I explained about MVD being the most common heart disease in dogs and with the cross, you would not be eradicating the problem, but hoping to put it back in its place old age. Health testing and health protocols are as important in cross breeding as any breeding, so don't let cross breeders fob you off with the myth above, to excuse the fact they have done no health screening of the parents of your pup.

Showing the mitrial valve closed when healthy

What have we learnt so far ?

Maybe I'm an idiot ? Maybe it would be best to just literally bang my head against the wall ?
Seriously have we learnt anything ? We have learnt that MVD is bad in Cavaliers and that crossing them is not a cure, but a means to getting onset of MVD later rather than earlier in a dogs life.
If you want more indepth information on MVD, research and treatments for this condition take a good look at the CavalierHEALTH.org website at http://www.cavalierhealth.org/mitral_valve_disease.htm

Showing normal mitrial valve and abnormal leaky mitrial valve

To breed or not to breed the Cavalier ?

With MVD so bad in Cavaliers, one has to question the sanity of using them in a breeding program. Why not just let them go ? The world will not spin off its axis because a manmade breed of dogs goes extinct and the aspect of cruelty could be brought forward in breeding dogs with a high probability to develop MVD. So what drives me forward and what reasoning can I bring forward to proportionate breeding dogs that have a high probability to develop MVD ?

Heart cross sections showing normal and prolapsed mitrial valve when valve closed

Now if I look at this in the cold light of day, I could easily let them go. Looking at the stats, the probability of breeding cross breeds with MVD and then you throw the chances of syringomyelia into the melting pot, it has to be said, "that it may be kinder to let them go."I'm going to struggle to justify myself here, but I will have a go and see where we end up. 
Over thirtyfive years ago my mother turned up with a Cavalier called Kerry, can't remember how Mum came by her, but I remember she was an adult when we got her andwas ruby in colour. She was our first cavalier and the first time we had a Toy breed dog, as all the dogs we had normally were workingdogs like spaniels, terriers and I recall as a small child a labrador and we did have one setter, some were pure and some were crosses. Kerry though did not consider herself a Toy dog and she saw no reason why she should not be in every way a proper spaniel, which included coming home often with half a hedge attached to her and when on a good scent to have selective hearing. She started my admiration for these little spaniels. She also had another important characteristic, she loved to be loved and could take as much of the stuff as you wanted to give her and along with a very tolerant nature, she seemed the ideal family dog and from her have followed more of these lovely little spaniels, giving me loyal and loving companionship throughout the years and with my children have proven their value has family dogs, showing tolerance to often rough little hands and obvious protectiveness of their little human pack members. I also have many funny, happy memories of these little spaniels, along with the inevitable sadness of their demise.
"Sentiment is all well and good" I hear you say and maybe that is it, why I try to improve the health because I don't want this type of dog to be remembered, I want people to experience what I have and have had with them. A lot of pure breeds frankly are in a mess health wise, but I fear that we should not be to hasty to throw the whole breed out with the bath water, as we will lose even more genetic variation from the domestic canine and within some of these gene pools I think we have some things worth trying to save. With the Cavalier it is the temperament that for me, is their defining attribute, spirited little fellows, that defy their size in valour, through hedgerow and cover, if allowed the excursion and neither needy or aloof.
 So I feel that the temperament is something worth trying to salvage from this breed and to amalgamate into a small spaniel type dog, improving the health, I believe it can be done. If we get real, breeding any animal (I include humans in that) has an element of risk, even if you were able to screen them for every known hereditary condition, because of good old mutation, so I have to weigh up the risks when breeding. 
The fact is MVD is the most common heart condition in dogs generally and seeing it in old dogs we can understand why due to the fact that the mitrial valve as explained above does the hardest job of the four valves in the heart as it works with the largest and strongest heart muscle, so it stands to reason, that this valve, we will most often see a problem with, if there is going to be a valve problem in the heart. At the moment we have yet to hear of any of our Cavapoos being diagnosed with onset of MVD before they are five years old ( I'm touching wood, as I type this) and being realistic, with the first outcross, if that figure carries on then I have actually achieved a better statistic for the onset of MVD than in the pure Cavalier, as statistics worldwide are around 10 % of Cavaliers have MVD at one years old and this rises by 10 % each year.
Using the Poodle as my first cross breeding with the Cavalier I think will lower the statistics for early onset MVD. MVD is seen in Miniature Poodles as all breeds, but can crop up as early onset slightly higher than the general dog population and small dog breeds on average suffer more with MVD, so although I think that the statistics for MVD go the right way using the Miniature Poodle as a cross,  I feel that our next crossing with the Brittany has the potential to give better results with MVD onset, as Brittany's are a medium sized breed which suffer with minimal heart problems within the breed. So at the moment I feel the risks outweigh the potential to improve the condition in trying to keep alive the spirit of these little dogs. I'm going to quit now, while hopefully I'm ahead in trying to explain myself, it's hard to put what you feel sometimes into words, so I'm going to finish on a photo of me having a cuddle with Smudge and hopefully this moment caught by my son says more than all my ramblings above. Yep, I'm ending this blog on a thick treacly layering of sentiment ! 

Smudge and me have a cuddle with Henry watching us