Dogs cannot digest whole fruits and veggies. Their digestive tract is unable to break down the cell walls of such foods (or so I've read). So if you want your dogs to get more of the benefits out of fresh veggies, you'll need to break them down by such methods as food processing, grinding, juicing, or steaming.
But whole veggies can still be fed to dogs as a low-calorie, all natural, fresh treat.
Here's an old video of Junebug, a dog we fostered a couple of years ago, enjoying a carrot.
Junebug was on the "Urgent" list at Lake County Shelter, a shelter that is notoriously overcrowded all the time. With the help of a team of volunteers, she was transferred from Lake County to Sonoma to Berkeley, where we picked her up to take home with us to Antioch. A mix of lab and pit (we think), Junebug was one of the best dogs we've ever fostered--well-behaved, submissive, friendly to all dogs and people, and not overly energetic. Just goes to show what hidden gems can be found at shelters, and that black dogs shouldn't be overlooked as often as they are. The family who eventually adopted Junebug from us (and boy were there a lot of people interested in her!) was very lucky to get such an all-around wonderful dog.