How Much Water is Too Much or Too Little?

Two people wrote me this month with two very different questions about how much water their pets are drinking.

I think their stories can help answer questions you might have about your own pets, so let’s take a look.

One wrote in to say “My cat is drinking 4-5 cups of water a day, is there something wrong?”

That definitely sounds like too much to me, and it raises some specific concerns in my mind. Diabetes, thyroid disease and kidney disease are conditions that are common in cats who are drinking much more water than normal.

So if this happens to your pets, I recommend taking them to your veterinarian and getting standard blood work-up that will easily rule out some of the more common possible problems, such as diabetes or kidney disease.

The blood work can also rule out other possible reasons a cat would be drinking too much, such as a bad urinary tract infection, inflammation of the pancreas or elevated thyroid levels.

This is a good idea for dogs too, but dogs can get some conditions, such as Cushing’s disease, which don’t show up in simple blood work.

By the way, this owner did a nice job by keeping track of her cat’s water intake. Any time you suspect your pet is drinking too much or too little, try to measure how much the pet is drinking. That way you can tell your veterinarian something specific when you discuss the problem. (Of course, it’s a little trickier when two pets share the same bowl.)

Bigger and more active pets will drink more than smaller and more sedentary ones, but your veterinarian will take those things into account.

I also got a letter this month from the owner of Sassy, a 6-year-old Yorkie. “My problem is she does not drink any water. I have tried giving her 3/8 cup of water with 1/8 cup of milk, and with a lot of coaxing she will drink it,” the letter writer says. Sassy also gets chicken bits in ¼ cup of water at night, but won’t drink water or broth afterward.

Great question, and here is the good news: This sounds to me like enough water for a small Yorkie who only weighs a few pounds. By all means, contact your veterinarian and ask for the blood work described above to be on the safe side. Also, urinalysis and blood tests will quickly answer whether your pet is dehydrated.

One additional note: I would avoid broth, which tends to be high in sodium, as well as milk. Some pets, like some people, are lactose-intolerant.

The nice thing to know is that most of the time, pets naturally know when to drink water and when not to. As long as your pets have easy access to water, they’ll usually drink the right amount. 

When it comes to the quantity of water, a lot of factors come into play, including the type of diet they are on. Animals on dry diets will drink more than animals on a canned diet. The main exception is when they’re sick.

So keep an eye on the water bowl. Make a note of it if you notice a big change, such as if the water level never goes down — especially if that happens in combination with any other signs such as anorexia, vomiting or diarrhea. And the same is true if you notice a big change in the other direction, such as when you’re suddenly filling the water bowl four times a day.

Once you notice a change, measure your pet’s water intake as best you can and contact a veterinarian.

And one other water-related note: If your pet is peeing in inappropriate places, that also can indicate some of the same health problems described above.