Chocolate
Garlic
Onions/chives/leeks
Macadamia nuts
Avocado
Alcohol
Yeast dough
Coffee/tea/caffeine
Grapes/raisins
Raw/undercooked salmon or trout
Peach/plum/cherry pits
Cooked bones (Not poisonous, but can splinter)
Xylitol (an artificial sweetener found in some peanut butter, candy and gum)