Mix ground turkey, zucchini, seasoned bread crumbs, onion, egg whites, parsley, garlic, salt, and pepper in a large bowl. Form into 12 patties.
Heat a skillet over medium heat; arrange patties in skillet and cook until no longer pink in the center and juices run clear, about 4 minutes per side. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).