When to give your dog water during a trip will depend on several factors, including the size of your dog, the temperature and whether or not you are engaging in physical activity. Larger dogs are going to need more water than smaller dogs and may require more water breaks. You’ll also want to offer water more often during tough hikes and when the weather is warm—use your own thirst as a good cue. When you stop for a water break, provide your dog water as well. Also, keep an eye on your dog. If you notice excessive panting or they seem tired, those could be signs that your dog is dehydrated and needs water right away.