Vegetables can be part of a healthy canine diet. Dogs have difficulty digesting raw vegetables, and certain veggies may actually inhibit thyroid function in dogs with thyroid problems, so it's important to prepare them correctly. Cooking, steaming and freezing, then thawing and fully mashing vegetables renders them edible. Avoid feeding dogs starchy vegetables, which can lead to weight gain, gas and stool problems.
Broccoli is chock-full of phytonutrients, which are not found in meats and animal food products. While it is unclear whether dogs can absorb plant nutrients or use phytonutrients, ongoing research continuously returns new benefits, such as helping protect against carcinogens. Broccoli is a good source of B-vitamins and minerals. Broccoli is high in fiber; be sure to steam or cook it before offering it to a dog.
Cucumbers consist almost entirely of water, but they are low-glycemic (non-starchy) and contain trace amounts of important vitamins and minerals, including vitamins B6, B12, A, E, K, folate, calcium, iron, magnesium, phosphorus, potassium and zinc. Feeding pickled cucumbers to dogs is not recommended.
Another non-starchy vegetable, cabbage brings Vitamins B1, B2, B3, B5, B6, B9, C, and calcium, iron, magnesium, phosphorus, potassium and zinc to the plate. Cabbage can be served cooked or steamed, though you'll want to limit quantities if you choose to serve it raw.
Celery may sound like an unusual choice for pet food, but it's loaded with vitamins A, B6, B12, C, E, K and minerals calcium, copper, iron, magnesium and zinc. (dogillness.org) Another of celery's components, sedanolide, has been found to lower occurrence of tumors in lab animal research and is also known to serve as an acid neutralizer.
Raw vegetables should comprise no more than 20 percent of your dog's diet; cooked veggies, no more than 40 percent. The bulk of the dog's diet still needs to come from meat and protein.
Introduce vegetables slowly into your dog's diet, working up to the full percentage as he or she gets used to the new food. Mix vegetables into the dog's regular food and meat, and don't introduce too many new veggies at once; integrate them into the diet one at a time.
If your dog experiences diarrhea or ample stools, reduce the percentage of veggies comprising the diet.