CSS height:auto for all types except SVG

don't know if it is possible, but I'd like to scale all images on my site with the following:

.myClass img {
    height: auto;
}

However, all *.svg-files shouldn't match that pattern. Is there a way to do this via native css?

I found something like this:

.myClass img[src$=".svg"] {height: auto;}

But that seems to trigger only for svg-files. Trying to use != seems to be syntactically incorrect.