What happens if a dog is not given water in summer?

If a dog is not given water in summer, it can suffer dehydration and heatstroke, which threaten its life. Water is vital for normal body function; without enough intake, the body loses water through urine, breath, and sweat, causing dehydration and electrolyte imbalance, then headache, nausea, vomiting, diarrhea, fainting, kidney failure, and death. Also, in summer heat a dog is easily affected by temperature and can get heatstroke; without enough water to regulate temperature, its body heat keeps rising and causes heatstroke symptoms.