Depends on whats happening in the video.
There are some videos where you don't need music or talking because the visuals do all the work. But there are some cases where you need to put something in to fill that emptiness in the video.
In this case, a dog video, whats going on in it?
Are they wrestling? Are they sleeping? Are they having fun? Whats happening in the video determines how you go froward in regards to editing.
If their just chilling and not doing much or just playing, stick some funky/happy music in the background and your good to go.
But, if your dogs are fighting or trying to do something/figure something out, then a voice over is good to explain to the viewers whats going on in the video.