Subaortic Stenosis in Four Free-Ranging Eurasian Lynx (Lynx lynx) from the Alpine and Jura Populations in Switzerland.

As part of wildlife conservation efforts, the reintroduced Eurasian lynx (Lynx lynx) populations in Switzerland are the subject of ongoing health surveillance. Cardiac pathologies, such as heart murmurs and histopathologic changes in the cardiac tissue, including intramural cardiac vessels, are frequently observed. Here we describe four cases of subaortic stenosis (SAS), a congenital heart disease rarely reported in felids, in free-ranging adult male lynx from Switzerland. The affected lynx presented macroscopically with grades 1 to 3 of SAS. Histopathology confirmed characteristic subvalvular fibrous tissue as well as myocardial fibrosis and arteriosclerosis. Clinical data for one lynx, including the documentation of a systolic heart murmur, provide further case-specific insights. Our findings suggest that SAS might be linked to the recurrently noted cardiac pathologies and could be associated with the low genetic variability of lynx in Switzerland. This highlights the importance of integrating health and genetic data into conservation strategies to preserve healthy, viable wildlife populations.