Why Is My Pet Drinking So Much Water?

Have you been filling up your dogs’ water bowls more often? Taking them out more frequently to pee? Or scooping a lot more wet cat litter? Polyuria and polydipsia is defined as urinating and drinking more than usual. It is a clue our pets are having health problems.

Our pets cannot tell us what is bothering them. If you notice your dog or cat drinking & urinating more than usual, bring them in for a health check. The earlier a diagnosis is made, the earlier we can start appropriate treatment.

how much is too much?

Excessive drinking in our dog or cat is defined as:

  • consuming more than 100ml/kg per day for dogs (e.g. Your 10kg dog is drinking more than 1L of water per day)
  • consuming more than 60ml/kg per day for cats (e.g. your 4kg cat is drinking more than 240ml of water per day)

Excessive urination is defined as more than 45 to 50ml of urine/kg per day (for both dogs & cats) but it is difficult for pet owners to measure. Watch out for behavioural signs such as going to the litter tray more often, waking up at night to urinate, accidents inside the house.

common diseases that cause polyuria and polydipsia (pu/pd)
  • Hyperthyroidism (common in older cats, rare in dogs)
  • Cushing’s disease (common in older dogs, rare in cats)
  • Hypercalcaemia 
  • Diabetes mellitus 
  • Acute or chronic kidney (renal) insufficiency
  • Liver (hepatic) disease
  • Uterine infection (Spaying your female dog/cat will prevent pyometra, a serious infection of the uterus.)
  • Lower urinary tract disease => Read about Bladder Stones

Read about Cody the diabetic puppy here

Few things to observe at home which may help with the diagnosis of your pet’s condition 

Measure the amount of water intake at home over a few days to determine if your pet is really drinking excessive amounts. Sometimes, a diet change (especially from wet to dry food) or foods/treats high in sodium content can cause your pet to drink more.

  1. Is the PU/PD sudden or gradual?
  2. Is there difficulty with urination, e.g. straining or passing blood?
  3. Is your pet eating the same amount but losing weight?
  4. Has your pet been vomiting?
  5. Has your pet been taking steroids (like prednisone) which are known to cause PU/PD?
take your pet for a vet check if you determine that water intake is indeed excessive

Complete Physical Examination

Your pet’s body condition, temperature, mucous membrane colour, breath odour, heart rate and abdominal palpation will shed more light on the possible underlying cause of PU/PD.

  • Pets with renal failure may present with a uremic/foul breath.
  • Pets with liver disease may present with liver enlargement and jaundice (yellow discolouration of gums and skin).
  • Pets with Cushing’s disease may present with a pot-bellied appearance , hair loss and thinning of skin.

Full Blood Tests & Urine Test

  • Kidney markers, liver markers, thyroid hormone and blood glucose can rule in or out renal disease, liver disease, hyperthyroidism and diabetes mellitus.
  • A urinalysis (urine test) can also determine the presence of a lower urinary tract infection or other underlying diseases.

Depending on initial test results, other diagnostic tests may be recommended. E.g. An ultrasound to diagnose uterine infections, Cushing’s disease & severity of kidney or liver disease.

Treatment can start once a diagnosis is made

In many cases, PU/PD will resolve when the underlying conditions are regulated. In renal disease, PU/PD is usually a permanent state. Never restrict your pet’s water intake. Provide ample water at all times to prevent dehydration.