What is Polydipsia in Dogs? Causes, Diagnosis & Treatment

Polydipsia in dogs is an abnormally increased thirst leading to excessive water intake beyond what is normal for the dog’s size and activity level. Typically, a dog is regarded as polydipsic when it drinks more than 100 millilitres per kilogram of body weight each day regularly.German shepherd puppies or other breeds may appear to drink more after exercise or activity, but ongoing excessive drinking often indicates an underlying health problem requiring veterinary attention.

Common Causes of Polydipsia in Dogs

Polydipsia is usually a symptom rather than a disease itself, and can be triggered by various medical and behavioural factors. Common medical causes include:

• Chronic kidney disease (CKD): Damage to kidney function can impair water balance regulation.
• Diabetes mellitus: High blood sugar causes increased urination and thirst.
• Hyperadrenocorticism (Cushing’s disease): Excess cortisol production leads to increased drinking and urination.
• Urinary tract infections: Irritation can cause frequent urination and polydipsia.
• Adrenal gland disorders: Addison’s or overactive adrenal glands affect hormone balance.
• Pyometra: Uterine infections in unspayed females often increase thirst.
• Liver disease and infections: These can disrupt normal kidney and hormone functions.
• Certain cancers: Such as lymphoma and anal sac adenocarcinoma can cause polydipsia.

Other causes include behavioural or environmental factors such as:

• Psychogenic polydipsia: A rare behavioural condition where dogs drink excessively due to boredom or stress, without underlying physical illness.
• Environmental factors: Heat, pain, or stress can also increase water intake temporarily.
• Medication side effects: Some drugs, including corticosteroids, promote thirst.

How Is Polydipsia Diagnosed?

Veterinarians diagnose polydipsia through a combination of history taking, physical examination and diagnostic tests, including:

• Blood tests: To check kidney function, blood glucose levels, liver parameters, and hormone levels.
• Urine analysis: To assess urine concentration and presence of infections or abnormalities.
• Imaging: Ultrasound of kidneys, liver, and adrenal glands may be performed to identify structural changes or tumours.
• Water deprivation test and synthetic ADH trial: To evaluate kidney response and hormonal regulation if diabetes insipidus is suspected.

Treatment Options for Polydipsia

Treatment depends on the underlying cause diagnosed by the vet. Examples include:

• Chronic kidney disease: Supportive care with free access to fresh water, dietary management, and medication to slow progression.
• Diabetes mellitus: Insulin therapy and dietary adjustment to control blood sugar.
• Infections: Antibiotics for urinary tract infections or pyometra.
• Endocrine disorders: Medication to regulate adrenal or thyroid conditions.
• Behavioural polydipsia: Environmental enrichment and behavioural modification.

Prompt veterinary treatment is essential to improve prognosis and quality of life for affected dogs.

When to See the Vet

If you notice your dog drinking more water than usual and frequently emptying water bowls throughout the day beyond normal activity or environment factors, it is vital to consult your vet for a thorough check-up. Early diagnosis and treatment increase the chances of successful management.

Conclusion

Polydipsia in dogs is often a sign of an underlying health issue, ranging from kidney or endocrine diseases to infections or behavioural factors. Responsible pet ownership means observing your dog's drinking habits closely and seeking veterinary advice promptly if excessive thirst occurs. This approach helps ensure your beloved companion receives proper care for optimal wellness and comfort.