Keep Them Hydrated
Heat stroke is one of the most common hiking-related ailments for dog. "On the first nice day of the year we always get a big influx in the clinic. Ease your dog into it when the weather gets warm," O'Sullivan says.
Always bring water for your dog and offer it any time you feel thirsty. Dogs can drink from clean streams as a matter of last resort, but keep them from drinking standing water. Dogs, like humans, are susceptible to giardia and leptospirosis.
When you return home, monitor your dog's water intake. "Dogs don't necessarily self regulate. Some will drink so much they throw up," says O'Sullivan, suggesting that you offer just a bit at a time. If a few hours after the hike your dog is still panting, consider taking its temperature — you'll have to do it rectally to get an accurate reading. Dogs run between 100.5 and 102.5 degrees, though O'Sullivan isn't worried until your dog is in the 104 to 105 degree range for more than a few hours. Then call the vet.