TDK conference 2017

Hypertrophic cardiomyopathy is today the most common heart disease amongst cats and one potential cause of sudden death. It is a disease with a progressive nature that affects primarily middle aged males. It is a disease that has been genetically connected to certain sarcomere gene mutation in two unrelated breeds of cat, Maine Coon and Ragdoll. Due to its genetic correlation, breeding programs have been established. The first breeding program in Sweden was introduced 2004 by the Maine Coon breeding organization and since then other organizations like PawPeds and SVERAK have joined in. The goals of these were to limit HCM in the population without major impact on genetic breed variation.

The aim of this study seeks to evaluate the breeding recommendations established in Sweden 2004. The other goal was to compare PawPeds database to similar international studies with emphasis on sex predisposition and disease onset in the Swedish population.

The database used includes 2070 unique SVERAK registered Maine Coon cats that were echocardiography screened at least once. 584 of these cats were also screened an additional time. The results of the second screening show a prevalence of either 3.8% or 8.9%, depending on if equivocal cats are considered positive or negative for HCM, and a decreasing prevalence trend is evident during the years of data collection (2001-2015). HCM diagnosed cats decreased from 10.5% to 3.9%. Results also confirm a statistical predisposition amongst older male cats.

DNA screening for the MYBPC3 – A31P mutation was performed on 254 cats that also endured echocardiography screenings. The DNA results show an overall mutation prevalence of 20.5% in the cohort compared to 30% in many other studies.

The results of the analysis of both screening methods in this study indicate a lower overall prevalence of phenotypic and genotypic HCM amongst the Swedish Maine Coon population compared to studies conducted on other populations. Based on these results the breeding recommendations in Sweden have been successful in decreasing HCM prevalence. They should therefore be continued the way they are structured today. Until further reliable diagnostic methods are available a combination of echocardiography and DNA screenings are the best diagnostic methods available today. In the future hopefully new diagnostic methods, biomarkers or genetic test will be available to accurately diagnose HCM prior to breeding age so the disease can be eradicated.