We love our dog, too! Never would we intentionally recommend a plant that would be harmful to any animals, especially domestic cats and dogs. But if you look up plant toxicity information you will find many landscape plants are considered "toxic." That does not mean all landscape plants will kill your pets (or you.) Toxic might refer to a rash or to vomiting, or, yes, even death. Do your research but also turn on your critical thinking cap.
One tree we often include in our designs is Eve's Necklace (Sophora affinis.) It's native to North Central Texas, stands about as tall and wide as Crape Myrtle, and is tough as steel. You might be familiar with the glorious Texas Mountain Laurel (Sophora secundiflora) native to Central Texas. Many a spring morning I was guided by its intoxicating sweet fragrance as I walked through campus in San Marcos. (Pardon the digression.) Eve's Necklace represents the best of Texas' natural beauty. It's durable and versatile: Eve's Necklace grows well in sun or shade, and prefers little-on-the-dry-side soil along rocky creekside embankments. Plant any time of year but late fall or winter is best. Water it in, hand-water a couple of times per week, and gradually scale back to 1" per week. By year two Eve's Necklace should survive on ambient rainfall.
Eve's Necklace puts on a lovely display in early spring. Its pink blooms smell heavenly. Black seedpods that look very much like necklaces dangle from its limbs much of the year. These seedpods may cause digestive problems if ingested but we will continue to include them in our designs. It's unlikely that we or our pets could reach our mouths 6+ feet into the air to nibble on a black seedpod necklace.
If you have a dog that digs or likes to lie on the cool foliage, don't use tender plants. Instead of planting shrubs or perennials in planting beds, incorporate pottery into the beds and fill them with colorful annuals and perennials. If your pet is losing his eyesight, avoid prickly plants like yucca, agave or cactus. If your pet runs along the fence, integrate the pathway into your landscape. Believe me, it's easier to modify the landscape to accommodate your pet than the other way around.