Your dog needs its own water on the trail, not a shared bottle cap. A collapsible bowl weighs almost nothing and clips to a pack, so there's no reason to skip it.
A tough, packable bowl that doubles as a food dish. Clips to a pack and lasts for years.
Check price →Squeeze to pour, release to reclaim the extra. Great for quick drinks without stopping to set up.
Check price →Cheap, light, and clips anywhere. Does the job for casual hikes.
Check price →Sturdy silicone that holds its shape better than flimsy fabric bowls.
Check price →Water storage and bowl in one unit, so it's one less thing to juggle at a rest stop.
Check price →Fabric bowls pack smallest, silicone holds shape better, and squeeze bottles are easiest one-handed. Plan on roughly an ounce of water per pound of dog per hour in heat, and carry extra. In many desert parks there's no water on the trail at all.