Hey,
Yes, they certainly are very stubborn and will only eat what they like. If we only gave her dry food she would eventually get use to it and eat it because she would know that she wouldn't get anything else, however, we also give her meat, bones, eggs, fish, milk, yoghurt so she knows that she will get something better next time and will only eat the kibble if she is starving (late in the evening) or if its mixed with other food. Very clever.