Drinking excessive amounts of water is called polydipsia, and it can be a sign of disease. Dogs may also drink more water than usual when they are hot or tired from exercise and need to replenish the water in their bodies.
How can you tell whether a dog is drinking too much? It helps to have a baseline for normal behavior first. If you’ve owned your dog for a while, you should be able to identify when something about her habits changes. You can also buy an automatic waterer that measures consumption; being able to see how much water has been consumed in a day by glancing at the measurements on the waterer’s side can prove very helpful.
As a rough estimate, a dog generally needs between a half-ounce to a full ounce of water per day per pound of body weight. In other words, a tiny Chihuahua may only need a few ounces of water per day. A 100-pound Mastiff might drink nearly a gallon.
These estimates will go up on hot days or days when the dog does a lot of exercises. Dogs sweat through their paws and by panting, and water is necessary to replenish the moisture lost by those activities.
Also bear in mind that dogs also get water from their food. If your dog has been eating moist canned food and switches to dry kibble, she’ll likely start drinking more to compensate for the difference in moisture content.
If your dog is not drinking enough water, dehydration can set in. It’s important to check for signs of dehydration, such as poor skin elasticity and tacky gums, if you suspect that your dog is not drinking enough water. On the other hand, drinking too much water can be a sign of some serious issues as well.
What Causes Polydipsia?
Polydipsia, or excessive drinking and thirst, is commonly caused by diabetes, Cushing’s disease, hypercalcemia, pyometra and metabolic problems.
These illnesses are all complex and generally present with other symptoms as well. In the case of diabetes and Cushing’s disease, excessive thirst may be the first symptom you notice.
If you’re concerned about your dog’s water intake, it’s important to get her to the vet right away so tests can be run. The veterinarian will want blood and urine samples to test for infection, white blood cell count, anemia, blood sugar, and many other factors. These laboratory tests can identify the underlying cause of your dog’s excessive drinking so that proper treatment can be given.
What Happens if a Dog Drinks Too Much Water?
The right amount of water in the body is essential for maintaining a balance of electrolytes. Drinking too much water too quickly can throw off the electrolyte balance, leading to hyponatremia, or inadequate sodium levels. Also called “water intoxication,” hyponatremia can lead to serious health complications and even death in some cases.
It’s quite rare for a dog to drink enough water on its own to cause water intoxication, although some dogs will develop a behavioral obsession with drinking and will need to have their water intake monitored and perhaps even controlled with a vet’s guidance.
A much more common cause of excessive water intake and hyponatremia is playing in a lake or pool; fetching toys in the water or diving repeatedly into the water can lead to ingesting excess amounts of water. Dogs that like to bite at a hose or sprinkler may also ingest large quantities of water in a short period due to the pressure the water is under. You’ll want to exercise caution with this type of play and encourage the dog to take plenty of breaks away from the water to reduce these risks.