Traveling can sometimes disrupt a dog's routine and increase the risk of diarrhea. To prevent this, ensure that your dog has access to clean drinking water throughout the journey and avoid feeding them unfamiliar or potentially contaminated food. Stick to their regular diet as much as possible and try to maintain a consistent schedule for meals and bathroom breaks. If your dog is prone to stress-related diarrhea, consider using natural remedies such as calming supplements or pheromone sprays recommended by your veterinarian.