gif animation not playing on refresh on wordpress

Question

i am displaying a gif image on my wordpress site - when i refresh the page the gif is being cached at the final frame. I would like to make it so everytime the page is refreshed the gif restarts from the beginning. is their any code (php) i could add to the functions.php file in order for this to take place.

Thanks.

Tried a few different options on stack overflow such as:

<img id="gif" src=""/>
<script>document.getElementById('gif').src="path_to_picture.gif?a="+Math.random()</script>

and

var src = 'http://i.imgur.com/JfkmXjG.gif';
$(document).ready(function(){
    var $img = $('img');
    $('#target').toggle(
        function(){
            var timeout = 0; // no delay
            $img.show();
            setTimeout(function() {
                $img.attr('src', src);
            }, timeout);
        },
        function(){
            $img.hide();
        }
    );
});