Last week this column touched upon the question of how much to feed a dog. Although feeding your canine pal isn’t rocket science, the matter still requires finesse. Many dogs, if allowed access to unlimited quantities of food, will become obese within weeks.

Watering a dog is much simpler. It is theoretically possible for dogs to drink water to the point of death. However, in practice this almost never happens. This means that you can follow one simple rule when it comes to water and your dog: Always have plenty of fresh water available.

My pal Buster’s water is poured out and freshened twice daily, with every meal. He always has access to it and is allowed to drink as much as he wants.

So far I imagine this column hasn’t contained any revelations. Everyone knows dogs should be allowed to drink water. But what if something seems wrong? What about dogs who seem to drink too little water or too much?

First, remember that few dogs drink too little or too much water on an everyday basis. Different dogs have individual needs and idiosyncrasies. There is likely no problem if one of your dogs seems to drink more water in general than another one over the course of his life.

The trend to track is your dog’s overall water consumption relative to his own lifetime average. It turns out that changes in water consumption can be symptoms of significant health issues in dogs.

Of course, not every change in a dog’s thirst represents a significant problem. Dogs, like people, will drink more water on hot days or after a lot of exercise.

However, changes in water consumption that are not related to such lifestyle and environmental changes can represent health problems. Dogs may drink substantially more water if they suffer from kidney disease, diabetes mellitus (also known simply as diabetes), or a glandular condition called Cushing’s disease. Certain medications, such as prednisone, may cause markedly increased water consumption.

Markedly decreased water consumption can be a sign of nausea (such as might be caused by gastroenteritis, inflammatory bowel disease, or a gastrointestinal foreign body). It also can be a late symptom of severe metabolic problems. For instance, dogs with kidney failure may drink more water for several days or weeks, but then stop drinking water as the disease progresses and they become nauseated or too sick to consume anything by mouth.

Remember that water and urine are two sides of the same coin. Excessive water that is consumed has to go somewhere, and in most cases that somewhere will be urine. Dogs with medical problems leading to increased water consumption may ask to go outside more frequently or may begin to have accidents in the house.

But if your dog is having accidents, resist the urge to withhold water in order to spare your floors. Although in the above paragraph I implied that increased water production leads to increased urine output, in fact the opposite is usually true. Dogs who take medications such as prednisone or who have medical conditions such as kidney disease or diabetes produce more urine first. The loss of water in this way makes them thirsty, and they therefore drink more water.

That means that withholding water will cause your dog to become dehydrated, but is not likely to help your floors.

Changes in water consumption can be a big deal in dogs, and you will always get your vet’s attention if you mention them. If your dog’s water consumption changes in a significant way, don’t alter your watering habits at home. Instead, seek veterinary attention.

Get more essential pet advice from Dr. Barchas in our Ask a Vet archive.

Learn more about dogs with Dogster:

• 6 Ways to Thwart an Off-Leash Dog Rushing You and Your Dog
• On Dogs and Body Language: How I Learned to “Speak” Dog
• Aspirin and Ibuprofen: Are Human Pain Meds Safe for Dogs?

Got a question for Dr. Barchas? Ask our vet in the comments below and you might be featured in an upcoming column. (Note that if you have an emergency situation, please see your own vet immediately!)