Rescue won’t drink water on hikes

Adopted a rescue in March. She’s in great health, no problem eating or drinking—until we take her for a hike. She just refuses to drink water while hiking. She’ll consider a stream but generally isn’t into it. She’s thirsty, but avoids water.

We’ve tried 3 different nalgene/thermos/collapsible bowls as well as squirts of water from a camelback. No dice. Our other dog is lapping it up, but she’ll absolutely avoid drinking & even move away from me when I try to offer it to her. She’s super smart…so what’s the deal? She’ll go nuts drinking water the moment she gets home.

So is it just an environmental change / anxiety of some kind? Anyone else experience this or have suggestions?

We were thinking of tossing a treat in some water, since she’s motivated by food…🤷‍♂️