Sunday, 16 October 2011

HCM and PKD1 in Siberian Cats...a response to a breeders earlier post

A recent posting by a UK breeder regarding the condition HCM and PKD in Siberians contained inaccurate information. I responded to this post but it seems the person in question has chosen to ignore my comment.

Here is some information about HCM in cats.

General opinion is that HCM is caused by a DOMINANT gene. SRI have had some anomalies in certain lines and a theory of triggers and suppressors has been put forward, (source conversation with Tom Lundburg). However it is acknoledged that not all pedigree records are correct and that more data has to be gathered and the more people who participate in sharing loses of cats with HCM instead of hiding them, will improve the future for all breeds as this progressive disease is in most populations of pedigree and non pedigree cats.
There are many 'strains' of HCM in the cat populations, I think there are at least three identified in the Siberian to date?
Regarding inbreeding. You will only have a increased number of affected cats if you use a HCM cat. If one parent have one HCM gene there is a 50/50 chance of passing on the condition.
If both parents have one HCM gene this increases to a 75% chance of offspring being affected
If one cat carries two HCM genes all offpring will be affected.
Remember, these probabilities are for EACH kitten and not a percentage of the litter.
As we have only had a handful of reported cases in the UK it is prudent to monitor your own cats and do follow ups of offspring. I must point out that HCM and its 100s of strains has been in the human population for some time and research is still in its infancy.....

PKD1 in Siberians
Some information about testing your cats from UC Davies
It is likely that PKD1 in Siberians will only manifest itself in cats whose origins include Persian roots or breeds using Persians as permitted outcrosses or where breeders have added these outcrosses to the gene pool. As we do not have reliable documentation about the foundation cats ancestry, or you suspect you cats ancestry may include such cats, a test may be prudent. However, if there is a strain of PKD in Siberians unique to this breed, as yet, no test has been approved. Monitoring of own cats and offspring and any occurances can be monitored and then that line tested and information shared.

It is important for those of us who breed this wonderful cat to be accurate in our publication of infornation. Many readers do not question the sources they read and can be misinformed.
NB Happily, in six years of owning and breeding Siberians, to date we have no reported cases of HCM/PKD1 cats in our foundation cats onwards :). If this changes I will cetainly let SRI know.


  1. Shirley - thanks for the information and links - which I feel are important for both breeders and owners alike.

    HCM scanning of Siberians right now is the only way to fully determine the condition, and it is important that all information is maintained and forwarded (openly and honestly) to SRI - in order that we can, hopefully, find a DNA test (as we currently have for Maine Coon and Ragdoll). However, the DNA test for these two breeds isn't 'definitive' always - so again, there seems to be room for manoevre so to speak.

    I think that if we choose to scan our cats for HCM then we are doing the right thing - and of course, it is an individual breeders choice whether or not to do that. It isn't always available in one's area, and it is expensive - There is, without doubt, Persian blood within some Siberian lines - and therefore again, as breeders, its important that we are aware of such things and breed accordingly. Basically - we do as much as we can in an effort to ensure that our cats are healthy. The problem with HCM of course is that even scanning a cat - and it being shown as clear - doesn't mean, unfortunately, that it will remain that way, as in truth - that scan is only valid on that day.

    I do hope that SRI can find an answer, but they can only do that with the co-operation of breeders and owners who have suffered HCM at some point. I think its a problem whereby sometimes 'fingers are pointed' and then people won't buy kittens etc., and so things are swept under the carpet.

    I know that I am attending a lecture next month on HCM and there has been talk that this may be filmed. If it is, then I'm sure it will be of use. Likewise any notes which may be available, I'm more than happy to distribute to anyone who would be interested. The lecture is being undertaken by a leading Cardiologist - and we are lucky that he's taken the time to do this - to educate breeders - predominantly Bengal breeders - but everyone is welcome.

    Lesley x

    PS - thanks again for the links x

  2. Thanks for your input Shirley. Nice to get the clearer picture. As you say some breeders post then can't deal with the flak, they never learn either do they ??
    I have my cats blood tested for Pro BNP(TM). Not all vets think this test is the best or most accurate but after speaking with the lab who do this test I'm more than happy to test mine this way. The lab is called IDEXX and it's in the UK.
    My vet won't do an echo unless this test result shows there's a problem. As I say not all vets agree but more and more are now doing this test.

    Like many other illnesses we will never wipe them out but we can at least try to lessen the gene being passed down.

  3. Thankyou Lesley and Jackie for your positive comments. I think working together on this is the best way forward. I dont perceive we have a huge problem in the UK gene pool at present, and monitoring our lines should keep it this way.
    My vet is very wary of the ultrasound test for reliability. I know a breeder who had her cat tested as a parent was diagnosed with HCM at 5yrs old. She said her cat was stressed to the point she would not do it again, she did have a negative result and I know several offspring of the HCM parent that have been used for breeding in the UK and none to date have developed any symptoms.
    I hope the lecture Leslie is attending is filmed, I would be intersted in seeing this.
    My vet checks my cats annually for any heart sounds, and is happy to refer on if she perceives any problems. They are particularly thorough with my kittens as I explained about HCM in Sibbys and as there are many manifestations of heart disease, and not always related to HCM.

  4. Angina Pectoris and Types checkout here
    Ischemic Heart Disease Details here
    Symptoms of Left Heart Failure and Signs click here