What is Polyuria – AKA Why is my Pet Drinking and Urinating So Much?

Increased water drinking and increased urination in dogs and cats is a common problem.

Because every animal needs to maintain water balance, any increase in water intake would result in greater elimination of urine and likewise, any increase in urination would result in a water deficit (dehydration) prompting an increase in thirst and water consumption. Some changes result from very serious medical problems and finding the cause of the changes is essential for your pet’s health.

Technically polydipsia is defined as greater than normal water consumption, polyuria is defined as greater than normal urination (based on volume). Normal daily water intake for dogs and cats ranges for 20 – 70 mL/kg per day. This is equivalent to a 10-pound cat consuming 2/5 – 1 1/3 cups of water per day or a 60-pound dog consuming 2 1/3 – 8 cups per day. Canned cat and dog food can be as much as 70% water, so if your dog or cat eats canned food the amount of water removed from the water dish each day must be adjusted to evaluate total daily water intake.

Pet owners can become suspicious of polydipsia and polyuria by changes in the daily routine. Needing to fill the water dish more often may suggest polydipsia in a dog or cat. Cats with polydipsia may lick water from the bathtub or shower when wet or may suddenly appear when a water faucet is turned on. Polyuria in a dog often presents itself as more frequent trips outside to urinate or larger volumes with each urination episode. Polyuria in cats is often suspected when the litterbox needs more frequent changes.

Environmental, behavioral and medical changes can all influence the amount of water consumed. Examples of environmental changes causing increased drinking include food changes, increased ambient temperature, or exercise changes. Puppies will occasionally drink excessive water without any environmental or medical cause. There are more than twenty medical reasons for increased drinking or increased urination in dogs and cats. Some of the most common are kidney disease, diabetes mellitus and thyroid disease (cats).

If you suspect you pet is drinking or urinating more than normal an appointment should be made with your veterinarian to discuss possible causes. Typically blood and urine tests are initially performed in addition to a physical exam to determine if there is a serious problem or if more testing is indicated.