Why does my dog drink so much?
Drinking a lot and urinating a lot is also known as polyuria (urinating a lot) and polydipsia (drinking a lot), or PU/PD for short.
A dog that drinks and urinates a lot may be suffering from one of the following conditions:
Kidney problems
With kidney failure, the kidneys can no longer filter the blood properly. This leads to increased urination and therefore increased drinking. Read more: Kidney problems in cats and dogs.
Urinary tract infections
Cystitis or an infection of the urinary tract causes more frequent urination. If the kidneys are also affected, this can lead to increased thirst. Read more about Bladder problems in dogs.
Diabetes mellitus
With diabetes, the dog urinates more because of an elevated blood sugar level (glucose is excreted in the urine and draws fluid with it). This causes increased thirst. Typical symptoms: drinking a lot, urinating a lot, eating a lot and losing weight.
Cushing’s disease
A hormonal condition in which the body produces too much cortisol. Symptoms: drinking a lot, urinating a lot, eating a lot, panting and a pot belly.
Liver problems
The liver plays a role in regulating fluid and sugar levels. Liver disease can lead to thirst and nausea.
Uterine infection (pyometra) in unspayed female dogs
A life-threatening condition in which the uterus fills with pus. The dog drinks a lot, has a poor appetite and is often lethargic.
Hypercalcaemia (for example due to malignant lymphoma)
Too much calcium in the blood can cause increased urination and therefore increased drinking. This can be caused by cancer.
Diabetes insipidus
A rare condition in which the body’s water balance is disrupted. Dogs with this condition drink extremely large amounts.
Psychogenic (behavioural) excessive drinking
Can a dog drink more because of psychological issues? Yes, some dogs start drinking more due to stress, boredom or compulsive behaviour. However, this is rare and should only be considered once all medical causes have been ruled out.
Medication
Some medicines, such as corticosteroids (for example prednisone), can cause increased thirst.
Other symptoms you may notice if your dog drinks a lot
Because excessive drinking can be caused by many different conditions in dogs, the symptom ‘drinking a lot’ may also occur alongside other symptoms. This can help indicate the underlying cause.
- Dog drinks a lot and vomits: This may indicate liver or kidney problems.
- Dog has diarrhoea and drinks a lot: In this case, increased drinking may compensate for fluid loss. Watch for signs of dehydration. You can support your dog with additional electrolytes if necessary, such as NutriCareVet Oral Rehydration Sachets.
- Old dog no longer eats but drinks a lot: This is a warning sign. It is often a sign that there is an underlying physical problem. Possible causes include kidney failure or a uterine infection in an unspayed female dog.
Does a dog with heart failure drink more?
With heart problems, increased drinking is usually not a direct symptom. However, some heart medications, such as diuretics, can cause your dog to urinate more and therefore drink more.
