🩺 Why Is My Cat Drinking So Much Water? Vet Guide 2025

By Dr Duncan Houston BVSc – Ask A Vet Blog Writer

1. What Is Polydipsia?

Polydipsia refers to excessive drinking—generally more than 100 ml/kg/day or about 1.5 oz per lb body weight—often paired with increased urination (polyuria) :contentReference[oaicite:3]{index=3}. It may be the first sign of an underlying health issue.

2. When to Worry 💧

• Does your vet suggest >100 ml/kg/day? That’s a red flag :contentReference[oaicite:4]{index=4}.
• Notice excessive thirst + frequent urination or accidents?
• Are there other signs—weight loss, vomiting, appetite changes?

3. How to Measure Water Intake

• Refill the bowl daily and note volume added.
• If multiple pets, observe each separately if possible :contentReference[oaicite:5]{index=5}.
• Use smart bowls that track drinking per pet.

4. Why Cats Drink Too Much: Top Causes

4.1 Chronic Kidney Disease (CKD)

Diseased kidneys can't concentrate urine, so cats drink more. CKD is common in older cats and shows up as dullness, vomiting, and increased thirst :contentReference[oaicite:6]{index=6}.

4.2 Diabetes Mellitus

High blood sugar leads to excessive urination and compensatory drinking. Watch for weight loss, ravenous appetite, weak back legs :contentReference[oaicite:7]{index=7}.

4.3 Hyperthyroidism

Overactive thyroid boosts metabolism, increasing thirst and appetite. Often seen in cats around 13 years old :contentReference[oaicite:8]{index=8}.

4.4 Other Causes

• Urinary infections or kidney stones
• Liver disease and certain cancers :contentReference[oaicite:9]{index=9}
• Electrolyte imbalances like high calcium or low potassium :contentReference[oaicite:10]{index=10}
• High cortisol from Cushing’s disease—rare but possible :contentReference[oaicite:11]{index=11}
• Rare behavioral form: psychogenic polydipsia :contentReference[oaicite:12]{index=12}

5. How Vets Diagnose It

• History & physical exam: Look for weight changes, coat, and hydration.
• Blood tests: Kidney function, sugar, thyroid levels, liver enzymes.
• Urinalysis: Specific gravity <1.035 indicates dilute urine :contentReference[oaicite:13]{index=13}.
• Urine culture: To check infections.
• Further diagnostics: Ultrasound, endocrine tests (e.g. cortisol).

6. Treatment & Management Options

6.1 Kidney Disease

• Low-phosphorus prescription diets
• Manage blood pressure, hydrate regularly
• Phosphate binders, supplements

6.2 Diabetes Support

• Insulin injections and low-carb diets
• Regular glucose tests and weight control

6.3 Hyperthyroidism Care

• Anti-thyroid drugs (e.g., methimazole)
• Radioactive iodine or surgery in suitable cases

6.4 Treating Other Causes

• Antibiotics for infections
• Manage liver disease or electrolyte issues
• Explore psychogenic causes if all else ruled out

7. Home Care Tips

• Keep water fresh, clean, and multiple bowls around
• Use water fountains to encourage drinking
• Ensure moisture in diet—wet food is ideal
• Keep a log of daily intake and urinary habits
• Track weight and alert vet for sudden changes

8. Assisted Care with Ask A Vet, Woopf & Purrz 🛠️

• Ask A Vet: Share intake logs or lab results for immediate guidance.
• Woopf: Offers non-spill and filtered drinking systems.
• Purrz: Provides moisture-rich diets and supplements ideal for cats with CKD or diabetes.

9. When to Act Now 🚨

• Water intake above 100 ml/kg/day
• Frequent urination or accidents in the house
• Symptoms of illness: vomiting, weight loss, weakness
• No improvement in days or sudden onset of polyuria

10. Key Takeaways ✅

• Polydipsia is often an early warning sign of serious illness.
• Measure water intake and track urination.
• Common causes: CKD, diabetes, hyperthyroidism.
• Diagnosis via blood and urine tests followed by targeted treatment.
• Support home care with fresh water, appropriate diet, hydration logs.
• Brands like Ask A Vet, Woopf & Purrz enhance ongoing care.

11. Final Thoughts

Increased thirst in cats is not just thirst—it's a symptom. Early recognition, accurate diagnosis, and timely treatment can dramatically improve your cat’s quality of life. If you notice sudden or persistent increased drinking, consult your vet or contact Ask A Vet. Your action could be life-changing. 💧❤️