I don't know what to plant if you exclude anything that might be toxic to dogs. Only in recent years have I seen the very long lists of plants toxic to dogs and included are such things as ivies, hollies, rhododendron(?), andromeda, hosta, peonies, iris, some daisies, some begonias, hellebores (lenten rose), and many other things frequently found in home gardens.
My advice would be if there's a puppy coming to hold off on planting the garden for a year or two. In my experience puppies are like deer . . . they'll taste test lots of things. But when they're older and trained they leave just about everything alone. The plant I worry about with dogs is wild mushroom and I try to get rid of it if I see it coming up.
For shady spots I like bleeding heart, both old fashioned and the smaller, longer blooming one, foxglove (definitely toxic), hosta, pulmonaria, astilbe, hellebore, lily of the valley, and adjuga (but only the dark leaved one which has deep purple flowers). Among my favorites are peonies, iris and day lilies but these all require a fair amount of sun to flower properly. If you need ground cover, you can't beat pachysandra (my husband calls it "the vinyl siding of the plant world"). It likes shade, takes care of itself, doesn't die during droughts, stays green in the winter, spreads but not out of control,won't climb trees, and doesn't show the effects of dogs going on it.
eta: For anyone who might be interested there is a long list of flowering plants toxic to dogs at www.aspca.org/pet-care/poison