You have an eye for detail. Try smooth-sanded gesso on masonite for a ground. The sharpness of close-up foreground hair and blades of grass will really jump when edges are not diffused by the weave of canvas.
On edit: You may already know this, but a small, long-haired brush they used to call a rigger (for painting rigging on sailing ships) is perfect for painting close-up hair, whiskers, and fur. And regarding previous comments about the brightness of acrylics, you can subdue brightness where you might not want it by the judicious and very light addition of neutral shades of grey or brown to the brighter colors, or a lighter glaze over a neutral underpainting. It took me a while to fine-tune that technique, but then, I've been at it professionally for nearly 60 years, so I'm starting to get the hang of it. My preferred medium is watercolor. 
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