Sorry, most plants will not enjoy being covered in dog urine. Deciduous plants will be slightly more able to handle it than evergreens, but beyond that it's best to protect your plants from constant urination. It really depends on how much and how often they are being sprayed. The more mature a plant is, the better equipped it will be to handle it. For example, larger trees will do better than saplings. You can prevent dogs from urinating on your favorite plants by using a spray repellent such as the one sold by Liquid Fence. You can buy it at most garden centers and home stores.