We have a two-year-old German shepherd who refuses to drink water when we are out on walks. She is obviously thirsty but won't drink from spigots, a cupped hand, or a water bottle. Often, she will refuse the water until we return home. We have started carrying a bowl made of fabric, and this is the only thing that gets her to take a little water. She is very focused, and when she knows she is potentially going for a walk, she will even refuse water at home. Is there something we can do to help hydrate her?