Next time, would you let your outward hounds get in on the action with this Kyjen Hydration System Dog Pack ($25) that holds up to 56 oz. of liquid? There's no sips on the go like a mountain biker, but the fluids can be squeezed out into a dog's mouth or dish when you reach the stopping point.
My super outdoorsy pals tell me that not packing more than one can carry is a key tenet of hiking preparation. So, while very necessary, toting water can really add up weight wise, even for just one person excluding the pet, too.