Just train your dog to drink from a regular water bottle with the pull-style nipple cap on it. Like those used by bicyclists, or as is often seen on bottled water for sale in convenience stores.
Done correctly, there will be little waste, no mess, huge convenience, and a happy dog. Our dogs get watered every 30 minutes or less if need be.

The trick is to teach your dog to use the bottle while tilting his head back. Put the nipple in back by his molars and it's all good from there. My wife taught her dog this trick when we started hunting him - slickest method around.

Brent

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BrentD, (Professor - just for Stan)
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