Hi there - sorry to hear about your dogs ailment. Our husky could never handle peas, cauliflower, broccoli, mushrooms, celery and legumes (beans, peas, lentils etc) (wind producing veggies) and used to pass wind like a trumpet if he did. When i spoke with the vet, she mentioned a rule of thumb. Dont give them anything you shouldn't eat when you are breastfeeding that gives your baby gas. ie:
acidic foods - tomatoes, bolognaise sauces, curry dishes - runs straight through.
Hope this feedback helps you out.