I had the problem to have a gif always loaded to the final step. The non-looping animated gif didn’t replay when the page was reloaded. Even when I was using “image.src” in javascript. Here is a quick trick to force replay a gif or reset it using js.
To reset or replay an animated GIF you can append a random query string in the url
// reset a gif in javascript
img.src = "your_image_url.gif"+"?a="+Math.random();
Tada!
Please note, that means that the GIF will be downloaded every time so keep it a small file.