When drawing animals, I think it's especially important to convey body language. It is their main communication tool in the animal world, so just by getting body language right you can already get a lot of leeway with other aspects of the drawing.
I suggest focusing on the basics first. Try to get the dynamics and energy of the animal into the rough lines of the drawing. Make the body flow, not stand oddly stiff, and don't worry about dimensions and negative and positive space. You'll want to focus on the shape of the animal.
You can try using the same basic sketch stages of a human body (circles, squares and lines) to get the rough skeleton of the animal down, then work from those to flesh it out.