Recommendations For Testing And Breeding
The following recommendations were worked out for the Maine Coons. Other breeds might be better off with slightly different recommendations, but for now the Maine Coon recommendations are the only ones we have. Hopefully we will get more breed specific recommendations for other breeds too later on.
Recommendations for testing:
The first HCM test should be done at the age of 1 and before the cat is used in a breeding programme. Further tests are recommended yearly until the cat is over 3 years of age. After that testing is recommended at the age of 5. When it comes to cats which have become very important for the general breeding stock or who are in an especially risky position (equivocal test result or having a close relative who has been diagnosed with HCM) it would be wise to do a test later as well, for example at the age of 8. Please observe that this is just a general point of view which has to be interpreted in each specific case individually.
Recommendations for breeding:
Also here the recommendations are a general point of view where you have to look at each specific case individually.
*) In these recommendations 'close relatives' means siblings, parents or direct offspring.
Diagnosed with HCM:
Cats with equivocal test results
Equivocal means that there was something found in the heart during the HCM test that is not 'normal', but at the time of the test it is not clear whether it is HCM or whether it could develop into HCM or not. It does not automatically mean the cat will develop HCM! Equivocal means exactly equivocal. The anomaly could be caused by other things like high blood pressure, kidney insufficiency, or something else. The cat could also have a normal variation on the 'standard' values, like e.g. the papillary muscles could be a bit larger than those of the average cat. Only further tests will show if this is HCM or not.
Cats which have received an equivocal test result should be handled as follows:
Re-test the cat's heart according to the recommendations of the specialist who examined the cat (it is common that they want to see the cat again in 6-12 months). If the cat is considered equivocal at the re-test, the recommendations depend on the age of the cat at the time of the latest test.
Equivocal, younger than 2 years:
Equivocal, 2-3 years:
Equivocal, older than 3 years:
Close relatives of affected cats
If a cat is diagnosed with HCM the following is recommended for its close relatives*:
Close relative has been diagnosed with HCM, the heart is normal on the cat itself when the cat is younger than 2 years:
Close relative has been diagnosed with HCM, the heart is normal on the cat itself at the age of 2-3 years:
Close relative has been diagnosed with HCM, the heart is normal on the cat itself when the cat is older than 3 years:
If the cat has been diagnosed with an equivocal heart and also has a close relative being diagnosed with HCM you should be extra cautious.
If you feel unsure about what applies for your cat, please don't hesitate to contact the contact persons for the health programme!