A dog regulates its own fluid needs and drinks more when its body requires it. A rule-of-thumb-sized dog of around 10 kilos typically drinks half a litre to a litre of water a day, but the figure varies a great deal with the weather, activity and what the dog eats. So when the water bowl suddenly needs refilling more often than usual, it is worth looking at your dog's daily life before you start to worry.
How much water is normal for a dog to drink?
A healthy water intake is roughly around 50 to 60 millilitres of water per kilo of body weight a day, but that is a guideline starting point and not a fixed limit. A dog weighing 20 kilos will therefore often drink a little over a litre a day under calm conditions. The amount varies from day to day, and the odd day of extra thirst rarely means anything. What is worth noticing is a lasting change. If your dog drinks markedly more than usual over several days in a row, without the weather or activity being able to explain it, that is the change you should keep an eye on.
Heat, exercise and play naturally increase thirst
The most common explanation for increased water intake is completely harmless. Dogs have few sweat glands and cool themselves mainly by panting, and that costs fluid. On warm summer days, after a long walk or intense play in the garden, thirst therefore rises noticeably. Dogs with a high activity level generally drink more than dogs with a more moderate daily routine, and the same applies to pregnant and nursing bitches, who use extra fluid. In all these cases, plenty of clean, fresh water is all that is needed. Make sure the bowl is always full, especially in the summer months when the need is greatest.
How food affects how much your dog drinks
What the dog eats has a direct bearing on thirst. A meal based on dry kibble contains only a little water, and the dog therefore covers a larger part of its fluid needs by drinking alongside it. If the dog eats PÂTÉ or wetter meals with a high water content, it gets some of the fluid through its food and correspondingly drinks less from the bowl. A switch from a wet to a dry meal can therefore in itself cause water intake to rise, without anything being wrong. Salty treats or leftovers from human food can also increase thirst briefly. If you want to add more fluid through the food, you can serve a meal with dog pâté or warm a little water into the dry kibble. If you are unsure how a change of food affects your dog's daily life, you can get guidance from ESSENTIAL FOODS' nutrition advisers by phone, chat or email.
Medication and life stage can change fluid needs
Certain types of medication make dogs drink more because they affect the fluid balance. If your dog is undergoing treatment, and it coincides in time with the increased thirst, that is a natural explanation you can discuss with your vet. Life stage also plays a part. A senior dog may have a different drinking pattern than an adult dog in its prime, and with older dogs it is especially worth keeping an eye on changes over time. If you want to read more about daily life and well-being in a dog's senior years, you can find inspiration in the guide best senior dog food.
When you should contact the vet about increased thirst
When the increased thirst cannot be explained by heat, activity or a new meal, and it persists for several days, it is time to contact a vet. Persistently increased water intake can be the body's way of signalling that something is changing, and it is the vet who can examine the dog and find the cause. If other changes accompany it, such as reduced appetite, more tiredness than usual or a different toilet pattern, you should not wait to seek advice. It is better to have a harmless explanation confirmed than to overlook one that requires attention. A vet can assess the overall picture, while you can keep an eye on the drinking pattern in everyday life and note when the change began.
How to keep an eye on your dog's water intake
The simplest way to spot a real change is to know your dog's normal consumption. Fill the bowl with a set amount in the morning, and notice how much is left at the end of the day. Then you have a baseline to compare against on the day you think your dog is drinking unusually much. Remember that several dogs in the household may share a bowl, and that a water jug or a fountain makes it harder to measure. A couple of days of notes gives you a far better basis for assessment, and it makes the conversation with the vet more precise if it becomes necessary. The daily attention to what and how much your dog eats and drinks is a good part of giving it the best conditions to thrive, and you can read more in the guide give your dog the best conditions to thrive.