If you have GIFs available of your products you can use them with Dynamic Ads.
NOTE: Some placements don't support GIFs. In those cases, the ad might feature a static image instead. Check the ad previews to make sure.
You need to have the GIF links in your catalog similarly as you would have normal images. The catalog and campaign setup then is same as with Dynamic Ads campaign.
When the campaign is running users will see the link or carousel ads with GIFs instead of images.
Let us know your experiences if you have tried Dynamic Ads with GIFs!