How can I loop animation in Blender through Viewer Node I've got a model running through a pixelate filter using the node editor, and am trying to figure out how to loop it.  I know how to loop it in 3D view, but when I click "render animation" it doesn't loop it in the Viewer node.

Is there a way to do this internally in Blender without having to export it?  Am I just missing something?  

I can view and render the image, and I can view and render the animation, but it only goes for a single iteration in the Viewer node.  It will loop continuously in 3D view, but it doesn't use the pixelation effect, as it is not being viewed through the viewer.
If you already rendered the animation, you can use Blender Video Sequence Editor. Just add clip with the animation and duplicate it as many times you need.
If you want to render already looped animation you can use NLA Editor. Just switch Dope Sheet to Action Editor and click on Push Down to move the animation to NLA Editor. Then switch to NLA Editor and from there you can select the strip and set Repeat in Playback Settings on the right tool shelf, to whatever number you need.