Vet settles debate on how much water your dog should drink in a day

As warmer temperatures are set to return next month and the three consecutive heatwaves in July alone, many dog owners are understandably wondering how much water their pets should be drinking each day. Unlike humans, dogs don’t sweat to cool down, which makes water consumption even more important in regulating their body temperature. Keeping your dog properly hydrated during the summer months is essential but knowing what’s “too little” or “too much” isn’t always straightforward.

While some owners worry their dog isn’t drinking enough, others may be concerned if their dog appears to be drinking excessively, and both ends of the scale can raise legitimate concerns. According to Carolanne Cicero, a registered veterinary nurse and In-House Veterinary Advisor at Bella and Duke, a good rule of thumb is that dogs should drink around 50 millilitres of water per kilogram of body weight per day which means about 22.7 millilitres per pound.

For instance, an 8kg dog (around 17.6 pounds) would need about 400 millilitres of water a day. A larger dog weighing roughly 30 kilograms, or 66 pounds, would need around 1.5 litres daily.

These figures are estimates, and if your dog eats wet or raw food, they’ll naturally take in more moisture through their meals, meaning they may not need to drink as much separately, Cicero explained. The amount they drink will also depend on the breed, age, and the amount of exercise they’ve done that day. 

One of the easiest ways to tell whether your dog is drinking enough is to check their eyes and gums, the expert said. Cicero wrote: “You can tell if your dog is drinking enough water by checking their eyes. A dog not drinking enough water will have dry, dull, and sunken eyes. Their gums will also be dry and sticky. You can also carry out a ‘tenting test’. 

“This test involves lifting up a small section of skin between your dog’s shoulder blades and letting it go. If the skin bounces back quickly, this can be a sign your dog is hydrated. However, if the skin takes a while to go back down or stays up in the tent position, your dog is dehydrated.”

Dogs that aren’t drinking enough may also show symptoms such as fatigue, thick saliva, dry nose, or loss of appetite. In more serious cases, they may vomit or have diarrhoea.

If your dog suddenly starts drinking much less than usual, don’t panic as this could be that they’re simply less active, getting water from other sources such as wet food, or even sneaking a drink from a dripping tap. That said, if their reduced drinking is paired with lethargy or other changes in behaviour, it’s worth speaking to your vet.

On the flip side, excessive drinking can also signal problems. If your dog is drinking water constantly and it isn’t unusually hot or they haven’t been very active, it might be due to an underlying health issue. Conditions such as diabetes, kidney disease, urinary tract infections, or even Cushing’s disease are all linked to increased thirst, the expert said.

If your dog doesn’t seem interested in drinking at all, there are a few easy ways to encourage them. One of the expert’s tips includes keeping you dog’s water bowlclean and changing the water regularly. 

Cicero warned: “The longest a dog can go without drinking is 48 to 72 hours. At this stage, your dog will be severely dehydrated and will need immediate treatment. If your dog has refused to drink anything for 24 hours, seek veterinary advice.”