When thinking about nutrition, most dog owners forget that water, not food, is the most important nutrient. All mammals, including humans and dogs can only last a few days without water. Within hours of water deprivation, the body begins shutting down blood flow to non-vital systems (skin, muscle, intestine, kidneys and other abdominal organs) in order to preserve water for the heart and brain. The water need of dogs is not a constant. The amount needed per day is dependent on many environmental and individual factors.
Basic Water Needs of Dogs
An easy rule of thumb is to provide at least 1-8oz. cup of water for each 10lbs. of body weight. The water bowel for every dog, Chihuahua to Great Dane, should always be larger than the food bowel. This amount of water is only a starting estimate. Individual dogs may need more water depending on their level of exercise, environmental temperature, type of food and medical health.
The Effect of Temperature and Exercise on Water Consumption
With the exception of the pads of their paws, dogs do not have sweat glands. Unlike us, they do not sweat. They cannot be cooled by sweat’s evaporation from the skin. Dogs must pant to evaporate water from their tongue and mouth in order to cool themselves. This results in enormous water loss from the body that needs to be replaced. Dogs that exercise heavily or are subjected to high temperatures lose massive amounts of water to stay cool. Working dogs or dogs exposed to extremely hot weather may need 3-6 times the normal amount of water. Dogs can never be offered too much water.
Dogs can become dehydrated during the cold winter temperatures also. Water bowels that are frozen do not allow dogs to meet their daily water needs. Sources for water for dog housed outside during the winter need to be protected from freezing. Dogs do not intuitively eat snow when thirsty.
The Effect of Food Type on Water Consumption
Diet will dramatically affect the water consumption of dogs. Dry dog food generally contains about 10% water. Wet, canned dog food is about 80% water. Dogs fed an exclusively dry diet will need more than their basic needs. Dogs fed an all wet diet may not need as much water. A combination diet (dry and wet) will need a variable increase or decrease in water needs.
The Effect of Disease on Water Consumption
Many medical conditions increase the need for water in dogs. Diabetes mellitus (sugar diabetes) and kidney disease increase the loss of water in urine. That loss is made up by increased thirst and water consumption. Hormonal diseases like hypothyroidism (underactive thyroid glands) and Cushing’s disease (overactive adrenal glands) are often diagnosed because owners tell their vets that their dogs are drinking more water. Liver disease and uterine infections in un-spayed females also increase water intake.
Excessive urination without increased water consumption occurs in other diseases. Dogs should never have their water rationed for increased urination. This could lead to dehydration and other medical complications. Always seek veterinary help when you notice that your dog’s water consumption and/or urination have increased.
Water Must Be Drinkable
Dogs should always be offered fresh, clean water. Bottled water is not necessary, but if your budget allows, go for it. Blue-green algae accumulation in unwashed water bowels or old sources of water is toxic to dogs.
The neurological symptoms caused by the ingestion of blue-green algae are often fatal. Swimming and drinking from ponds with these algae should also be avoided.
~Dr Ken Tudor
THE DOG DIETITIAN