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  • Debbie Sprenger

HCM development analyzed per breed (part 1) (nog te vertalen)


Feline Hypertrophic Cardiomyopathy (HCM) is a condition that causes the muscular walls of a cat’s heart to thicken, decreasing the heart’s efficiency which can lead to heart failure. HCM is the most commonly diagnosed cardiac disease in cats. HCM can also occurs in other mammals and in humans, but for this article we focus on the cats only.

There have been health programs set up for HCM for several feline breeds. Within this healthprogram, the cats have been tested by approved cardiologists or radiologists, and their results are send to PawPeds for registration in the health database. This has been done for many years and thanks to the breeders that participated within the HCM healthprogram, I was able to analyze the results that were gathered over the years.

HCM Healthprogram

The Maine Coon was the first breed that had a HCM healthprogram set up, starting from 1998. Then other breeds followed. In the table below you can see which year the program started. There are many more breeds that I have left out here, I’ve only picked the healthprograms that have more than 100 testresults. This data shows the total results for the whole period of the healthprogram.

I have followed the PawPeds databases to get the group of EMS codes that are registered together in one database. For example the Siberian and Neva Masquarade are registered together in one PawPedsdatabase sharing the same healthprogram.

The healthprogram advises to repeat the test at certain ages. As you can see by the 7th column, you can conclude that many cats have been tested more than once. Sphynx has the highest test frequency at 1,7 times per cat. The cats that had at least one diagnosis with HCM, is counted in the column HCM positive cats. A cat that has multiple results showing HCM, is counted only once. Results that were equivocal were not included in the HCM positive column, as equivocal is not HCM. PawPeds distinguishes different stages of HCM: mild, moderate and severe. In the table, those were all counted as HCM (column 8).

You can see from the table that the Maine Coon has the most cats tested within the healthprogram, almost 12.000 cats. Obviously the number of HCM diagnosed cats is therefor higher, but compared to the whole tested population, "only" 2,3% of the total tested cats got diagnosed with HCM.

Total cats with HCM diagnosis (1998-2020)

When you visualize the previous table, showing the total HCM cases compared to the total amount of cats tested, you will see the result in the chart below. This is the result of the total period of the healthprogram, which for each breed have a different starting date (shown in the table above).

Chart 2: Cats with HCM during whole healthprogram
Chart 2: Cats with HCM during whole healthprogram

How to read this chart? The number of cats tested you see next to the breed's name (n=). For example Siamese & Oriental have 131 cats tested with the healthprogram in the period of 2006-2020. Of those 131 cats, 3,8% got diagnosed with HCM, which comes down to 5 cats. The blue line shows how many cats are tested. The bars are ordered by amount of test results. The lower the bl