The short answer: It depends.
The long answer: Dogs are omnivores, so they can enjoy food that comes from animals and plants. Vegetables are packed with nutrients that can help keep your pooch’s body healthy and strong, but not all vegetables are safe for him. Vegetables that your dog can safely eat include bell peppers, brussels sprouts, cabbage, zucchini, peas, cauliflower, spinach, lettuce, asparagus, sweet potatoes, corn, celery, cucumber, carrots, broccoli, and ripe tomatoes. However, it is always advisable to check with your veterinarian regarding how much and how often your dog is allowed to consume each vegetable. Remember that some vegetables should only be fed to him in small portions or as occasional treats.
On the flipside, garlic, onions, spicy peppers, and mushrooms should never be fed to your dog. Additionally, he should not consume pickles, which are vegetables that have been soaked in saline solution for long periods of time.
How to feed vegetables to your dog: Always wash the vegetable properly, and take out the hard, inedible portions such as the seeds, stalk, and core. Whether you boil, steam, blanch, or grill the vegetable, be sure to cook it without using salt, heavy oils, savoury sauces, and artificial flavourings that would be harmful for your dog.
What to do if your dog accidentally eats a toxic vegetable: Observe your dog for any signs of poisoning. These may include vomiting, difficulty in breathing, drooling, diarrhea, agitation, tremors, convulsions, pale gums, and heart issues. If he displays any of these symptoms, take him to your veterinarian or animal emergency clinic immediately.
In summary: It is tempting to just feed your dog all the vegetables you eat, but as a responsible pet parent, you must find out which vegetables will benefit his body and improve his health. Do your research, and prepare the vegetables accordingly to avoid complications from arising.