If ur nintendog runs away,it sometime means that they feel neglected but they will come back.If they do leave they can also just b going to get u a present
If you're taking good care of your dog (Feeding it right, giving it water, and washing and bathing it), then it sure shouldn't be gone for 更多 than 10 seconds. If it's gone for a long time (about a 分钟 或者 more), then it may have run away due to neglection. When it comes back, give it lots of 爱情 instead of scolding it. Then, your Nintendog will know 你 爱情 it.