Animated SVGs won't start until the page is fully loaded

My site contains quite a few ads and it takes a while to load them. This is not a problem for sure, but I noticed that any SVG animations will draw the first frame instantly, but the animation only comes after the page has finished loading. SVG animations usually have a spinner / load icon. It really doesn't make any sense if it doesn't animate until the element it represents is loaded.

Is there a way to start the animation early?