Being an urban dog person, I always need to have plastic storage bags on me to pick up after my dog. You can use these to improvise a bowl if needed. Orignally tho, I did carry a water bowl as you described in my pack. However, I've switched to a small titanium bowl as detailed in this post . I use it to protect my dust masks from getting crushed and then also have the benefit of having a light, sturdy and rigid bowl for Sophie and I. In an emergency situation I don't mind sharing.

-john