My dogs like to eat bark, but not off of the trees.... There are many taste deterrents sold, but I have not found one that deters my dogs. ROPEL is the strongest that I know of. It can be obtained at gardening stores. Use gloves when applying. A session with a shock collar might work the best as long as the dog is not savvy (collar on vs. off). Is the dog bored? I used a strong reprimand and distraction to cure one of my dogs from digging. That is usually very hard to break.... everytime he started to dig, I distracted him with something else. Worth a try...