Your dog is about 80 percent water, and she needs to drink enough every day to stay in good health. Usually, healthy dogs drink the right amount of water on their own, assuming they have access. Unless your vet advises otherwise, provide your pet unrestricted access to fresh water at all times. Sudden changes in how much your dog drinks can indicate a health problem and should prompt a call to your vet.
Precisely how much water a dog needs each day varies based on a number of individual factors, including age, activity level, overall health, medical conditions and how hot it is outside. As a basic rule of thumb, though, a healthy dog should drink at least 1 ounce of water per pound of body weight every day. So, a 15-pound dog should consume at least 15 ounces -- or just under 2 cups -- of water daily. Ask your vet for a personalized recommendation about how much your dog should be taking in.
Wet Versus Dry Food
Whether you feed your dog canned food or kibble affects how much water she'll drink each day. The bulk of canned food's weight is from water, as it has an average moisture content of 75 percent. Dry food, on the other hand, typically contains just 6 to 10 percent moisture. Semi-moist food is also available and generally contains 15 to 30 percent moisture. If your dog eats canned food, she gets a considerable amount of fluids from her meals, so she won't be inclined to drink as much from her water bowl.
Polydipsia is the medical term for excessive thirst. It has a variety of causes, ranging from relatively harmless to quite serious. Foods high in sodium or sugar can make your dog thirstier, as can a diet low in protein. If your dog's eating something she's allergic or intolerant to, throat and digestive symptoms might be prompting her to drink more. Many canine medications cause increased thirst as a side effect, so check the labels of anything your dog takes. Of course, hot weather or lots of exercise enhance thirst, too. Polydipsia also presents as a symptom of numerous illnesses, such as liver and kidney problems, urinary tract infections, certain cancers, diabetes, hormonal imbalances, intestinal parasites and ingestion of a toxin.
Adipsia is the flip side of polydipsia -- drinking too little. If your dog isn't drinking enough, dehydration is an immediate concern. Untreated, it can quickly turn serious and even fatal. Common symptoms include dry mouth, lethargy, sunken eyes, anorexia, depression and behavioral changes. If your dog stops drinking, first clean her bowl thoroughly and provide new water. Physical trauma, stress and digestive upset sometimes interfere with a dog's desire to drink. Dental pain, viral infections, certain cancers, toxicity, a foreign body in the mouth or digestive tract, and pancreatitis are some conditions sometimes presenting with adipsia. Cognitive dysfunction is another concern in older dogs, who can forget to drink or have difficulty finding their water.
By Jon Mohrman
About the Author
Jon Mohrman has been a writer and editor for more than seven years. He specializes in food, travel and health topics. He attended the University of Pittsburgh for English literature and San Francisco State University for creative writing.