MRI scan

[Pinky]

I just wanted to get some views on this. I was talking to a breeder who owns a well known show dog. When I asked him about SM he explained that to get an MRI done in Ireland it costs in the region of €1200+ and the test itself is inconclusive. Even if the dog is clear on the scan it can still be a carrier of SM and pass it on to the pups. Any thoughts on this?

[pcfarrar]

Our last cavalier had an MRI scan done and it cost a few hundred pounds. But I think this was a special subsidised rate. I also believe you can get an inexpensive DNA test now.

[Alison_Leighfield]

The MRI done on that day is for that dog alone. It will tell you if that dog is clear of SM on that day. Dogs can also progress and develop SM at a much later age, a bouncy fit puppy and a young playful dog might not always stay that way as SM is a progresive disease and onset age is varied, so try not to assume that a dog will remain clear for its whole lifetime. There are recommended ages for scanning that breeders follow so that they can try to find their affected stock and withdraw them from any breeding.
How old is this dog in question? and do you know of any family history? is there clear around him? has he produced any clear scanned pups yet? go back and ask all this if you can, his answers will be interesting.
That dog may well produce affected even if clear itself, thats why it is so important to breed from MRI'd clear scanned dogs and bitches to see if this breeding does indeed make a difference to future generations of Cavaliers. Guess work is no good.

In my view it's a very poor excuse what he gave you, perhaps he simply doesn't want to know whats on the inside? If his dog was found to be affected then surely/hopefully that would end possible stud work as he shouldn't be bred from, and very possibly end his show career.

Hope some of this helps with your questions,

Alison.

[Karlin]

Consider that every indication is that this condition works in a way similar to MVD. Dogs that are heart clear and whose parents were heart clear til at least age 5 and completely fit with the MVD breeding protocol can still produce puppies with early onset MVD -- but the point is that it is *considerably less likely*.

No decent breeder would blindly breed cavaliers with no regard to the heart status of the parents, most importantly, but ideally knowing the lines as well. You do want to know that your breeding dog isn't the one unusual clear dog from a line with early ongoing heart problems.

Research in the Netherlands is showing pretty conclusively that clear dogs have other clear dogs around them in their immediate families. There's also a strong indication that affected dogs produce affected puppies whereas clear dogs produce clear puppies and mildly affected puppies.

With SM, believe me, breeders DO tend to know some of the dogs that have not scanned well and there are an increasing number of breeders who are making MRI info available on their lines and who are known for having dogs that have scanned well.

Anyone breeding in Ireland also should be aware that Geoff Skerritt at Chestergates Hospital in Chester will scan cavaliers for breeders in Cheshire for under €200 each. It is possible to take the early ferry, have the dogs scanned, and get the late afternoon ferry back. I had both my pet boys scanned in this way at my own expense and frankly, breeders complaining about costs in this way just don't cut it with me. The UK is full of very low cost schemes specifically for breeders and Irish breeders can use these too.

I suspect the more likely reason anyone has for avoiding scanning where these low cost schemes are easily available is not wanting to find their line is affected, and especially for stud dogs, this could seriously have an impact on the money the dog generates in stud fees.

[Bet]

May I chime in here .
It is known that A to A matings of MRI scanned Cavaliers have produced Off-springs with SM

I just dont know what the answer is .

NO-body seems to have definite proof that clear to clear MRI scanned Dogs will produce Puppies with no SM

At the moment .to help in this dilemma ,the Mode of Inheritance does'nt seem to be known
.
There is shortly to be guidance to be given to Breeders by Dr Sarah Blott ,who is Researching SM in Cavaliers at the Animal Health Trust ,in England ,for Breeders to have a Mating Program .

Bet

[sins]

Even if the dog is clear on the scan it can still be a carrier of SM and pass it on to the pups

I believe your breeder is being penny wise but pound foolish! If his dog was MRi scanned he would only lose the price of one pup at most, but actually gain in the long term by adding value to the rest of the dog's progeny if the scan came back clear.
Sins

[Karlin]

It is known that A to A matings of MRI scanned Cavaliers have produced Off-springs with SM

Bet, this point is noted by Alison and me but as also stated, this is very rare and in all the research studies so far, NO clear dogs have been produced in matings of dogs that were believed to be asymptomatic (and therefore assumed by their breeders to be clear but later scanned and found to have SM). Whereas clear dogs have produced almost no dogs with symptomatic SM and puppies on scans so far are either clear or have very mild status.

Inheritance is also not understood for MVD (sadly a situation set to continue as breeders refused to give enough heart info for the genome study for BOTH these conditions to have been analysed -- surely a crime in itself for the breed!!). Yet you yourself have argued strongly and passionately for years that dogs should be cardiac tested for the same reasons that people argue dogs need to be scanned -- every indication is the condition is strongly hereditary in the breed, the evidence is that breeding clearer dogs produces clearer offspring than breeding affected dogs, all else being equal. And there isn't a geneticist or researcher that believes the condition is not strongly hereditary, that I know of, in any country where research is being done -- dogs that are symptomatic tend to start to produce dogs that are also symtpomatic, as can be seen in several well known cases.

Given that breeders live with many dogs that many times are kept in kennels or separate dog quarters, the chance of observing symptoms also is low as many symptoms are not that pronounced until and unless the dog reaches severe status -- so I have no doubt that well intentioned breeders who do not scan are breeding symptomatic dogs that they think are not symptomatic. I have a deaf dog that came from a very health focused breeder who -- despite the fact that the dog was one of their personal favourites -- never realised she cannot hear. If this is the case with something as seemingly obvious as total deafness, I've no doubt it is very easy to miss the morning and nighttime scratching that is a common initial symptom, and may only happen after dogs are kennelled or off to the dog room, or before the breeder sees them in the morning. For example, I have absolutely no doubt my Leo would have been used at stud had I not bought him (this was the intention) because unless someone had him sleeping in the same room as themselves, they'd have missed all his growing symptoms between age 2-5, his prime breeding years, when he would scratch during the night or very first thing in the morning, never on walks though, no initial air scratching, no yelping, nothing.

I have spoken to Sarah Blott who definitely feels the condition is hereditary -- her goal is hopefully to discover the mechanism, eg to not understand IF but understand HOW. The problem is that breeders continue to not do scans, or work with her. More data is needed for her project to have any chance of success. Some actually feel there is already enough scan info out there to develop breeding recommendations based on DNA testing alone but the problem is that breeders have not submitted enough of the scan information that is already out there, and that is forcing breeders who do care, to continue to have to pay for scans.

Breeders and clubs could do much towards progressing research if there were some strong club and breeder support for the existing research programmes much less the work that will need to be done in future. I do know that several geneticists are not as hopeful as Sarah for the breed's future so really breeders should be fully backing her work as their best hope for having a breed to show in the years to come.

[Karlin]

This is what Sarah said in her presentation is Rugby (notes from Canadian CKCS Club):

SARAH BLOTT, B.Sc, M.Sc, Ph.D Department of Genetics, Centre for Preventive Medicine,
Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU

ìDr. Sarah Blott is a Research Group Leader at the Animal Health Trust (AHT) and is interested in the
development of breeding schemes for companion animals that combine state-of-the-art knowledge in
quantitative genetics with molecular genetic markers. She has a M.Sc. in Animal Breeding and a PhD in
Quantitative Genetics, completed at the Roslin Institute (Edinburgh).î

Highlights of presentation:
- Advises that presentation is to talk about ìhow to breed away from genetic diseases. Says that they
believe the disease (CM/SM) has a genetic basis.
- The 2 year Project is funded by the Kennel Club Charitable Trust (UK) and intend to look at 2 breeds;
the Labrador Retriever, because it has good hip dysplasia records and the Cavalier King Charles
Spaniel for Syringomyelia.
- Both are examples of complex diseases, are multifactorial and that we are not going to have a single
gene DNA test.
- Discusses persons she will be working with (Tom Lewis, a quantitative geneticist and Prof. John
Williams, a world expert in designing breeding schemes). Says they hope to come up with
recommendations and strategies to enable us to breed away from the disease (SM).

From: http://www.cavaliercanada.com/docume...TING_-_Website[1].pdf

Notes from the Rugby sessions. CDs are available of the actual talks themselves.

[Margaret C]

I think you should assume that every cavalier will probably carry one or more of the genes for SM, just as they will for MVD.
Puppies will get genes from both parents, some will be more lucky in the 'mix' they inherit than others, which is why you can get affected and 'clear' puppies in the same litter.
As Clare Rusbridge said in one of her earlier seminars, parents without early onset SM (two & a half years is the age that a cavalier is graded 'A' ) have more good genes to pass on than those affected at an early age.
No good breeder deliberately doubles up on faults.

I'm afraid this breeder is trotting out the standard excuses that are heard so often from those who fear what an MRI will show in their dog.
I presume that he would not mate together two cavaliers with early heart murmurs or slipping patella, but he is deliberately taking the risk of producing puppies that could have this really painful condition.

I have had so many phone calls from pet owners who have bought a cavalier from well-known show breeders & they have then spent months, sometimes years, trying to find out what is wrong with it.

There is a cavalier being shown, and winning well, that is limping and displaying obvious signs of discomfort in the ring. His owners say they want to make him into a champion & then they will put him in a pet home!
I hope they spell out to the new owner the prognosis for a dog with such early symptoms. There will be no chance of getting insurance.

It seems to me there is something very cynical & callous about campaigning a dog with obvious symptoms. The excitement and stress, together with the very long journeys, frequent bathing & almost continous brushing. A dog cannot say "please stop this is hurting" if the owners choose to ignore signs of SM
Where is there any consideration for the welfare of that dog?

Best wishes,

Margaret C

[Pinky]

Thanks for all the replies. The dogs he is breeding are over 3 so he said if they were symptomatic he wouldn't breed them full stop but I see Karlin's point about the possibility of missing the early signs of neck scratching. If I could find a breeder in Ireland who did MRI I would definitely get a puppy from them and wait as long as it takes as I do think it's important to support the breeders who are getting the MRI done but I am beginning to think they are non existent.