That depends on who you ask. I personally enjoy eating vegetables. I even like lettuce. In fact, I pretty much like anything that falls to the floor, including scraps of paper and stuff in the street.
Be that as it may, according to Kristie Leong MD in an article in therealowner.com, the following vegetables are good for dogs: “…green beans, cabbage, carrots, broccoli, squash, and most other green, leafy vegetables. Not only do these vegetables add healthy antioxidants to your dog’s diet, but they also are a significant source of soluble fiber and roughage which can promote intestinal health in your dog.”
As in everything you feed your dogs, don’t overdo it. It’s always best to feed a quality dog food. And of course lots of treats, in my opinion.
Here’s a list of food harmful to dogs, from peteducation.com