Dog’s don’t need electrolytes like people & horses do. They need water during & after exercise and carbs after exercise to recover. Sodium (like in gatorade) should be avoided. It will dehydrate the dog from the inside and can cause diarrhea and other problems up to and including killing the dog. Horseback field trialers for pointing dogs just give water during and after running/roading/hunting their string and then many will give Karo corn syrup after hard work to replenish carbs & glycogen.