How Important is Water to a Dog's Digestion?

Your dog should have fresh, clean water available to her at all times.
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Of all the nutrients your dog needs for a well-balanced diet, water is the most important, and it plays a key role in many aspects of your dog's digestive system. Water helps your pooch break down and digest the food she eats, facilitates the absorption of the nutrients from those foods and carries food waste from her body.

Water with Meals

Your dog needs a fresh supply of water at all times, especially when she eats, because water helps break down the bulk in food, facilitating digestion and nutrient absorption. The amount of water your dog needs to drink when she eats depends on the type of food she consumes. If you feed her canned food, which already contains 70 to 80 percent water, she may drink less water with her meal than a pooch on a diet of primarily dry dog food. Water is especially critical in digestion of dry dog food, because it rehydrates the food once it reaches the stomach, making it easier to break down and digest.

Digestion of Food

Water plays a role in every aspect of your dog's digestive system. It's in the saliva that moistens her mouth, tongue and esophagus to facilitate eating and swallowing. Once food reaches the stomach, water helps break it down then begin the digestion process. As food moves through the stomach to the small intestines, water plays a part in every organ that secretes the enzymes and acids that process the nutrients in your dog's food, including her liver, pancreas and gall bladder.

Elimination of Waste

In addition to carrying the nutrients through the digestive system and then delivering those nutrients throughout the body, water facilitates carrying waste through the digestive system and out of the body. After passing through the small intestines, food waste matter enters the large intestines where the feces are stored before elimination. Water plays a critical role at this stage, especially in older dogs, as aging often slows movement in the digestive system, leading to constipation.


While the large intestines store waste that is to be eliminated from the body, it's primary function is to help your dog maintain a healthy level of hydration. Because excess water is extracted and absorbed into the body through the walls of the large intestine, consuming too little water through drinking and eating not only makes it difficult for your pooch's digestive system to efficiently move and eliminate waste, it can lead to potentially serious health problems, including dehydration.