# HCM in Various Breeds



## pipje (Jun 29, 2011)

I found a detailed report regarding HCM in pedigrees and thought it might be of interest to some of you here. I found it very difficult to read (German, thank you Google Translate) but the report is based on results on PawPeds so is not representative of everyone breeding but only those responsible enough to test and open enough to publish the results. As you can imagine, there are also many who choose not to publish negative results or simply do not take part in such things.

As I am a BSH breeder, I focus on their results but it's surprising to know how terribly affected (MUCH worse than BSH) Persians/Exotics and Sphynxes are (yet for these breeds, HCM scans aren't expected yet). And for Bengals, those who were tested at older ages (8 and up) were all (100%) found positive for HCM 

For BSHs, the results (there're lots so I only put some which might be of interest):

i) The most common age group to be found positive/suspicious is between 18 months-3 years (do take note that even if a BSH is found positive, this is not necessarily a death sentence.They can sometimes live to a ripe old age)

ii) For BSHs, it is not too bad at around 7.6% of positive cats. Again, this is only for people who test and who are willing to publish the negative results. Persians/Exotics are at a whopping 19.5%! It's amazing that it's not expected for Persians/Exotics to be tested yet.

iii) On the same site but a different study: out of a study with 324 BSH cats (the first study I mentioned included over 2000 BSH cats), 85.7% BSHs were normal. The rest either tested positive (8.5%), suspected/equivocal (4.3%) or had other heart diseases (2.1%).

iv) Male cats have a much larger chance of developing HCM at 20.4% of males testing positive/suspected. Females only 2.1%. I guess I'll stick with girls for now

Here's the chart with some breeds and the prevalence of HCM in them:


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## Cerridwen (Jul 26, 2008)

Just keep in mind that the selection of study subjects (cats) isn't random. If all Bengals (exactly how many?) over 8 years of age have tested positive for HCM I'd guess that they have been tested either because they've had symptoms of heart disease or because they've had offspring that's tested positive for HCM/equivocal.

If I were to make a study in hip dysplasia in Swedish Devon Rexes we would much likely have a very high percentage of cats with HD. Not because it's common but because it's extremely unusual that Devon Rexes have their hips X-rayed and when they do they're X-rayed because there's a suspicion of HD or because a freak breeder like me have outcrossed with a breed that have some problems with HD.


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## pipje (Jun 29, 2011)

Cerridwen said:


> Just keep in mind that the selection of study subjects (cats) isn't random. If all Bengals (exactly how many?) over 8 years of age have tested positive for HCM I'd guess that they have been tested either because they've had symptoms of heart disease or because they've had offspring that's tested positive for HCM/equivocal.
> 
> If I were to make a study in hip dysplasia in Swedish Devon Rexes we would much likely have a very high percentage of cats with HD. Not because it's common but because it's extremely unusual that Devon Rexes have their hips X-rayed and when they do they're X-rayed because there's a suspicion of HD or because a freak breeder like me have outcrossed with a breed that have some problems with HD.


Yes, of course the study isn't completely objective as it does not cover all cats, all breeds but is dependent upon breeders who choose to take part in the study . I believe Bengals are expected to be HCM-tested and Persians/Exotics aren't yet but this is slowly changing (according to some Persian breeders, many Persian breeders still refuse to scan because they insist that this disease is not present in this breed. However, the Persian breeders I've spoken to say HCM is definitely present and they themselves have encountered them in their own cats).

Furthermore, even those (no matter the breed) who opt for scanning, most stop scanning once the cat is no longer used for breeding. Again, this is slowly changing. I do know many breeders who now scan their former queens at age 5,8 and 10 just to check (boys also, of course but these are often in service longer). Unfortunately, not everyone does this because HCM tests are expensive.

To answer your question about Bengals, 347 Bengals were included in the survey (that is to say, they were scanned). 6.6% tested positive/equivocal. The most common age group to be tested positive/suspicious is also less than 3 years of age but I cannot find the number of Bengals testing positive for HCM at age 8 and above (only that the various graphs state 100% but how many animals is not listed). 

For me, personally, I think the numbers for BSH are too positive. The real number of cats with HCM is probably higher than 7.6%. I have heard/read of so many incidents where it was just chalked up to "these things happen" but nothing was done (autopsy for eg.). Not so long ago, I heard about a 5 year old female who died from a heart attack giving birth. Well, to me this sounds suspiciously like HCM but the breeder certainly didn't report it nor perhaps she herself did not realise it could've been HCM.


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## spotty cats (Jul 24, 2012)

Many Sphynx breeders scan, some BSH do with it becoming more common, I've not heard of Exotic/Persian breeders scanning - which isn't to say they don't.

Bengal breeders that I know do, they'll only deal with others who also scan and there is a database for the results. There are often databases that are known to those in specific breeds, not always available to the public.


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## pipje (Jun 29, 2011)

Ah yes, you're right. I just had a look at the pedigree kittens for sale database and all the Syphnx kittens do have tested parents. 

I only know 2 Persian/Exotic breeders who scan. However, I am not a breeder of this breed so it's not like I know very many nor discuss these things! I just happened to meet someone sometime back and she was telling me this. Because she tests, it's even hard for her to get a breeding kitten from other breeders because they don't want to sell it to her. 

For BSHs in The Netherlands, HCM is now an expected thing (ie. if you don't scan, you're probably a BYB/not a very good breeder). It's quite a recent change (probably 2005/2006 is when it became common) and can also be felt on the price of pedigrees (sometimes on Dutch forums, you do get the ocassional post from interested people who ask WHY is the price of BSH kittens so high now? I bought my kitten 7 years ago for only 350 euro, why is it 550 euro now?! Ridiculous etc.).


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## Cerridwen (Jul 26, 2008)

Yes, 6.6% out of 347 cats makes 23 cats with HCM and I doubt many of them were over 8 years when diagnoses. I'd guess maybe a handful of them were that "old". If even that. Add to that that not all HCM is hereditary. It can occur secondary due to thyroid problems, old age and such. Here's a big problem at least in Sweden, whenever a cat is diagnosed with HCM everybody (even the vets) just assume it's hereditary and there's no follow up. If the HCM is caused by an overactive thyroid the cat is sick and needs treatment for the underlying cause.

When it comes to for how long to scan the experts I've spoken to have said there's probably no use keep scanning after 8 years of age. Not for breeding purposes. For the individuals sake you can of course keep scanning until the cat dies, if you think it's worth the stress.

I was one of three who was appointed to set scanning recommendations for Cornish and Devon Rex in the Nordic Rex Cat Association and because of that I've been in contact with many leading experts in both genetics and cardiology. One the cardiologists said plain out that scanning breeding stock at 2 and 5 years of age should be enough to reduce the HCM frequency in most breeds. Now, this is of course a compromise. Scanning is a stressful situation for many cats and it costs money (here it costs appr. 90 GBP per scan). Keep in mind that breeders have many costs: PKD1-testing, eye screening, PRA-tests, PK-deficiency tests, X-rays for HD, testing for infectious diseases, importing cats etc. The incitament for yearly testing until the breeding cats are 8 years is very low within breeds where the breeders don't experience problems with HCM. I don't even want to think about how much money I've spent on HCM-screening, without finding even one equivocal heart.

Within my breed (Devon Rex) the frequency of HCM is appr. 3%, using the information we have (Pawpeds and private collected information). 80% of our cats have yeast overgrowth and the number of cats with allergies and various skin problems are increasing. Despite this, HCM is the big health issue people are worrying about. That makes no sense. People are less willing to exclude an allergic cat from breeding than a cat with diagnosed equivocal.


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## OrientalSlave (Jan 26, 2012)

It's unfortunate that it's not possible to spot cats which are developing HCM before they are bred from - at 2 nearly all have had their first litter.


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## Jonescat (Feb 5, 2012)

It's interesting, these things are so difficult to assess as they have to be voluntary and therefore you can't get the complete picture. There is a great deal of concern about HCM in NFCs and one of my vets has stated that if a Ragdoll, NFC or MC is in his surgery, he assumes that HCM is present until proved otherwise. Looking at these figures it looks like a few other breeds need to be added to his lists. 

They (the Norwegian Forest Cat HCM DNA Research Project) are doing a UK NFC HCM survey currently which hopefully will help understand the risk. Also they are looking at blood tests, although these will only help identify the known gene. Blood tests will be a much less intrusive/expensive tool than scanning though if they prove reliable.


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## OrientalSlave (Jan 26, 2012)

Hopefully any gene tests for NFCs can be done on check swabs rather than blood samples.

HCM is a complicated disease in people, I suspect it is in cats as well.  However prevelence in people is lower - less than 0.5% - and I can't find it now but previously found a link suggesting there could be as many as 100 genes, or variations of (fewer) genes involved.


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## Jonescat (Feb 5, 2012)

And given that there seem to be different genes involved in each breed it is going to be very difficult to sort it out. It's an interesting point made earlier that there are other issues getting no attention while this one is in focus.

I really feel for breeders - many many diseases have a genetic component even if it is only part of the overall picture. Is it a case of a little knowledge is a dangerous thing?


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## pipje (Jun 29, 2011)

Cerridwen said:


> Yes, 6.6% out of 347 cats makes 23 cats with HCM and I doubt many of them were over 8 years when diagnoses. I'd guess maybe a handful of them were that "old". If even that. Add to that that not all HCM is hereditary. It can occur secondary due to thyroid problems, old age and such. Here's a big problem at least in Sweden, whenever a cat is diagnosed with HCM everybody (even the vets) just assume it's hereditary and there's no follow up. If the HCM is caused by an overactive thyroid the cat is sick and needs treatment for the underlying cause.
> 
> When it comes to for how long to scan the experts I've spoken to have said there's probably no use keep scanning after 8 years of age. Not for breeding purposes. For the individuals sake you can of course keep scanning until the cat dies, if you think it's worth the stress.
> 
> ...


I think if the disease is prevalent in the breed, then money has to be set aside for it. In yours, it's only 3% (and as you said, probably if the cat was tested, it was because they might have showed signs?) so it's understandable that one does not test for HCM. I don't test for PRA or HD etc. either- just what is necessary for my breed.

You noted that HCM can be caused by other factors. This is correct and is also why I would prefer to test my cats via echocardiogram EVEN if a genetic HCM test is developed for British Shorthairs. Like in humans, HCM is not only caused by one gene but apparently there are hundreds of possibilities.

In regards to stress, it is minimal. Honestly, the vaccinations/FIV/FeLV test etc. are more stressful by far (in my experience, due to the drawing of blood/injections). HCM is only shaving a bit of hair and absolutely no pain.

Considering that BSHs have a median discovery of positive/equivocal hearts of around 2.7 years or age, a scan at 2 and 5 years would be a little dangerous. Furthermore, BSHs are late-onset (although the data I read on pawpeds said 2.7 years of age, based on word-of-mouth, it is also often discovered in slightly older cats- for eg. between 3.5 to even once 7 years of age). Take note that these cats tested negative before this. Why this is important? So that especially studs can be stopped from producing more babies and also to notify those who have breeding kittens from the affected stud (girls also of course but girls produce less babies than boys!).

So my own policy is the average one for NL: test queens before a nest (and if I have extra money also when they are older), studs every year as per recommended (every year until around the age of 5/6 and then once every 2 years with the last being at the age of 10 years old).

What does irk me is some breeders (in NL) don't scan, yet charge the price of a scanned animal but that's another matter altogether



OrientalSlave said:


> It's unfortunate that it's not possible to spot cats which are developing HCM before they are bred from - at 2 nearly all have had their first litter.


Yes, correct. It's too bad and furthermore, tests are also not conclusive and indicative of the future (since the test is a snapshot of that moment only). Here, it is recommended that you test from the age of one year as it is sometimes possible to see signs of this in the echo already. One of my kitten buyers' cat (not from me) died at the age of just 1 year and 2 months. While no autopsy was done, I believe it was HCM (it sounds a lot like it. Her owners went on holiday and put the cat in a cat hotel. Cat then dies suddenly from heart attack while they were on holiday. The stress probably exacerbated her heart condition. She went for a full body check at her local vet just 2 weeks before the incident and he said her heart sounded healthy Granted he is not a specialist and he didn't do an echo, just listened to her heart with a stethoscope).



Jonescat said:


> It's interesting, these things are so difficult to assess as they have to be voluntary and therefore you can't get the complete picture. There is a great deal of concern about HCM in NFCs and one of my vets has stated that if a Ragdoll, NFC or MC is in his surgery, he assumes that HCM is present until proved otherwise. Looking at these figures it looks like a few other breeds need to be added to his lists.
> 
> They (the Norwegian Forest Cat HCM DNA Research Project) are doing a UK NFC HCM survey currently which hopefully will help understand the risk. Also they are looking at blood tests, although these will only help identify the known gene. Blood tests will be a much less intrusive/expensive tool than scanning though if they prove reliable.


Yes, I fear that if it was properly assessed, the results may be far worse for British Shorthairs. I mean, based on these results (7.8%), I may not bother to test to be honest (if I know my cats' background very well). Unfortunately, many breeders still keep very quiet about these things and there are many breeders who are also unaware of such things. Heck, not so long ago, I thought well, my queen is tested, her parents are tested, her grandparents are tested, heck even her great-grandparents are tested..well, I'm safe. Apparently not. Because actually, I don't really know what's happened to them since. Not all breeders will give out information nor can this information be found on the web (ie. yeah, great-grandmother was tested but that was at age 3. Is she still alive? Did she perhaps die at 10 years of age?I have no idea).



OrientalSlave said:


> Hopefully any gene tests for NFCs can be done on check swabs rather than blood samples.
> 
> HCM is a complicated disease in people, I suspect it is in cats as well.  However prevelence in people is lower - less than 0.5% - and I can't find it now but previously found a link suggesting there could be as many as 100 genes, or variations of (fewer) genes involved.





Jonescat said:


> And given that there seem to be different genes involved in each breed it is going to be very difficult to sort it out. It's an interesting point made earlier that there are other issues getting no attention while this one is in focus.
> 
> I really feel for breeders - many many diseases have a genetic component even if it is only part of the overall picture. Is it a case of a little knowledge is a dangerous thing?


That's why for HCM (because it is a complicated, sneaky disease) it is recommended that breeders continue to scan IN ADDITION to the gene test (if developed for other breeds) in the future.

Take note: I understand that in the UK, this is not done because it's stupidly expensive. I pay around 125-145 (depending on specialist and the clinic they travel to) euro per scan per cat. This is the most expensive test I have to do (FIV,FeLV,PKD, blood group and HCM) but it's still affordable. In the UK, it can cost 300 pounds(which is so ridiculous! I mean, it's a simple test- it requires an echo machine and yes, an expert reader but... 300 pounds for a 15-minute examination?). I think breeders in the UK could band up and ask for a quantity discount Langford does provide scans for 145 pounds now and they say further discounts might be possible.


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## spotty cats (Jul 24, 2012)

pipje said:


> Take note: I understand that in the UK, this is not done because it's stupidly expensive......... In the UK, it can cost 300 pounds(which is so ridiculous!.


Costs a bit here, yet it still gets done (around 480 pounds). Just comes with the breed, cost really shouldn't be used as an excuse.


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## Cerridwen (Jul 26, 2008)

pipje said:


> I think if the disease is prevalent in the breed, then money has to be set aside for it.


And this is kind of what it all boils down to, how do you determine if the disease is prevalent in the breed? Within some breeds such as the Sphynx it's just obvious because breeders find young cats become ill of HCM in early age. Within most breeds, it's not that obvious. The research is scarce and the research done almost never use random sampling.



> I don't test for PRA or HD etc. either- just what is necessary for my breed.


You have British Shorhair? Well, many Swedish BSH breeders are HD-testing their cats due to cases arising. Many of the cats with HD never show anything. I only started HD-testing because I use BSH in my outcrossing program. It was recommended by BSH breeders.

So, how do you assess if you need to test for something? It's not all easy.



> You noted that HCM can be caused by other factors. This is correct and is also why I would prefer to test my cats via echocardiogram EVEN if a genetic HCM test is developed for British Shorthairs. Like in humans, HCM is not only caused by one gene but apparently there are hundreds of possibilities.


I agree completely, the DNA-tests do not tell the whole story and cannot replace other test methods.



> In regards to stress, it is minimal. Honestly, the vaccinations/FIV/FeLV test etc. are more stressful by far (in my experience, due to the drawing of blood/injections). HCM is only shaving a bit of hair and absolutely no pain.


In my experience most HCM scans are quite stressful for the cats, but that's probably because I've attended many HCM clinics where many cats and their owners gather to scan 20-30 cats during the course of one day. Under these conditions many cats have to be sedated and my *extremely* tolerant old lady turned aggressive (taking blood for a FIV/FeLV-test is not a problem). Luckily I've found another vet who does everything under very calm conditions and now I have no problems. However, most cats here in Sweden are scanned under these more stressful conditions.



> Considering that BSHs have a median discovery of positive/equivocal hearts of around 2.7 years or age, a scan at 2 and 5 years would be a little dangerous. Furthermore, BSHs are late-onset (although the data I read on pawpeds said 2.7 years of age, based on word-of-mouth, it is also often discovered in slightly older cats- for eg. between 3.5 to even once 7 years of age). Take note that these cats tested negative before this. Why this is important? So that especially studs can be stopped from producing more babies and also to notify those who have breeding kittens from the affected stud (girls also of course but girls produce less babies than boys!)


.

I'd say that't less of a problem here in Sweden. Few studs are still fertile by that age and most breeders are responsible enough not to let their studs turn into matadors.



> What does irk me is some breeders (in NL) don't scan, yet charge the price of a scanned animal but that's another matter altogether


Yes, that's shameless but people will charge as much as they can. I test my cats more thorough than most other breeders of Devon Rex in Sweden and despite that I can't charge more than them. Actually I have lower prices since I work on an outcross program.



> One of my kitten buyers' cat (not from me) died at the age of just 1 year and 2 months. While no autopsy was done, I believe it was HCM (it sounds a lot like it. Her owners went on holiday and put the cat in a cat hotel. Cat then dies suddenly from heart attack while they were on holiday. The stress probably exacerbated her heart condition. She went for a full body check at her local vet just 2 weeks before the incident and he said her heart sounded healthy Granted he is not a specialist and he didn't do an echo, just listened to her heart with a stethoscope)


.

I'd be careful drawing such conclusions. There are many different kind of congenital heart defects in cats except from HCM. Just assuming it's HCM without an autopsy is quite dramatic.


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## pipje (Jun 29, 2011)

Cerridwen said:


> And this is kind of what it all boils down to, how do you determine if the disease is prevalent in the breed? Within some breeds such as the Sphynx it's just obvious because breeders find young cats become ill of HCM in early age. Within most breeds, it's not that obvious. The research is scarce and the research done almost never use random sampling.
> 
> You have British Shorhair? Well, many Swedish BSH breeders are HD-testing their cats due to cases arising. Many of the cats with HD never show anything. I only started HD-testing because I use BSH in my outcrossing program. It was recommended by BSH breeders.
> 
> So, how do you assess if you need to test for something? It's not all easy.


No, it is not easy but awareness is the first step. Sweden seems to be ahead of this so I will not be surprised if HD tests for my breed will also soon be commonplace here. For me, how I decide is based on awareness (so of course if HCM is a hot topic and you hear stories, you watch out more for it and will test). I do believe HCM for British Shorthairs is very real. I know enough cats who tested positive for HCM- many of these are still alive (as said, not necessarily a death sentence, some do not even need medication yet). Without testing, these cats would have been bred from and is it genetic? Not always but is certainly a big factor because if you look, the affected cats often have affected siblings/parent(s)/grandparent(s) etc.For me, 140 euros is well spent on something which gives me the feeling that I did what I could to not breed with an affected animal.

Oh and yes, when I know more of HD and that there is indeed a prevalence, I would set aside money for it. I am a small breeder so in that sense, I can afford to do it. Of course if someone has 15/20 cats, the costs are scary.



Cerridwen said:


> I agree completely, the DNA-tests do not tell the whole story and cannot replace other test methods.
> 
> In my experience most HCM scans are quite stressful for the cats, but that's probably because I've attended many HCM clinics where many cats and their owners gather to scan 20-30 cats during the course of one day. Under these conditions many cats have to be sedated and my *extremely* tolerant old lady turned aggressive (taking blood for a FIV/FeLV-test is not a problem). Luckily I've found another vet who does everything under very calm conditions and now I have no problems. However, most cats here in Sweden are scanned under these more stressful conditions.


 I am shocked by this. The HCM scans here are by appointment only so it's one-on-one rather than a large group of cats and people! Some specialists do sedate cats but personally, I believe most times this is not really necessary (if one-on-one) since it's not painful and really like a normal check-up at a vet :-D 
.



Cerridwen said:


> I'd say that't less of a problem here in Sweden. Few studs are still fertile by that age and most breeders are responsible enough not to let their studs turn into matadors.


Not many here are too but this is slightly changing. I see a trend where breeders prefer older males due to the awareness HCM is getting. To be completely honest though, I must say that older studs that are still in service here are in really amazing condition and really a positive addition to the breeding programme (the breeders who have them are excellent ones too). The stud I used last year is 13 years old and he is such a credit to the breed (last HCM scan at 10 years old). Anyway the reason why I said scans at a later age would be worthy is also because just because a stud is neutered does not mean his (owner's) responsibility ends there. If he has sired many babies (e.g. especially if he's a European Champion/World Champion whatever), you can bet he has his progeny breeding around the world. If he is affected, isn't it important information to pass on to the owners of his progeny? Now of course, if he is affected, the owner (in my eyes, quite understandably) may choose to keep it quiet due to outrage, guilt, who-knows-what. Of course these things cannot be helped (especially if developed at a later age) but it will cause unhappiness.

Anyway, this is partly why I'm too chicken to get a stud (although it is very tempting).



Cerridwen said:


> I'd be careful drawing such conclusions. There are many different kind of congenital heart defects in cats except from HCM. Just assuming it's HCM without an autopsy is quite dramatic.


True but since no autopsy was made (most people won't as they don't want to 'cut' into their cats and because it's expensive)... For me, better safe than sorry. I considered a very beautiful boy for my next stud but later found out his mother died giving birth to him from a heart attack. No autopsy was made. So I prefer to keep the risk as low as possible and will pick another boy


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