Vet Guide: Is Your Horse Drinking Too Much Water? 2025 🐴💧

By Dr Duncan Houston, BVSc

Water is essential for your horse’s health—but can they drink too much? The short answer is yes. While increased water intake is often benign and even expected in hot climates or with high-performance demands, abnormally high water consumption can be a sign of underlying health issues. 🧪🐴

In this 2025 veterinary guide, Dr Duncan Houston explores how to monitor your horse’s water intake, what counts as excessive, and when to seek veterinary attention. 💧🩺

1. What’s Normal Water Intake for Horses? 📊

Water needs vary with weight, activity level, and environment. On average, a 1,000 lb (450 kg) horse drinks:

• 💧 5–10 gallons (19–38 L) per day under normal conditions
• 🌾 Horses on lush pasture: 3–4 gallons (11–15 L)
• 🌞 In hot weather or with work: up to 15 gallons (57 L)
• 🍼 Lactating mares: May drink more than 15 gallons per day

Important: Always observe your individual horse—some drink more or less due to feed type, stall conditions, or temperament. 🧠

2. What is Polydipsia? 🧪

Polydipsia is the veterinary term for excessive water consumption. It’s typically defined as:

• 📈 More than 50 mL of water per lb of body weight
• ➡️ For a 1,000 lb horse, that equals ~13 gallons (49 L) per day

If your horse is drinking over this amount consistently—especially without heat, work, or lactation to explain it—something may be wrong. ⚠️

3. Signs Your Horse May Be Drinking Too Much 🔍

Aside from watching the water bucket, look for:

• 🪣 Buckets emptied quickly or repeatedly
• 💦 Excessive puddling around automatic waterers
• 🧻 Stall constantly soaked with urine
• 🧽 Constant urination or strong ammonia smell

Many owners first notice a change in urine output, not drinking—keep an eye on your stall bedding! 👀

4. Common Medical Causes of Excess Water Intake ⚠️

While occasional increases in drinking are normal, chronic polydipsia may point to a health issue. Two of the most common causes are:

🧠 Cushing’s Disease (PPID)

• Common in older horses (15+ years)
• Disrupts hormones affecting thirst and metabolism
• Signs: long hair coat, muscle loss, laminitis, excessive urination

🩺 Chronic Kidney Disease (CKD)

• Less common but serious
• Kidneys lose ability to concentrate urine
• Leads to dehydration and compensatory water intake

Other Potential Causes:

• 🧂 High-salt diets or supplements
• 💊 Certain medications (e.g., diuretics, corticosteroids)
• 🦠 Diabetes insipidus or mellitus (rare)
• 🌱 Excessive protein in feed

5. When to Call the Vet 🩺📞

Contact your veterinarian if you notice:

• 🚱 Water intake regularly exceeds 13 gallons/day in a 1,000 lb horse
• 🩸 Constant wet stalls or frequent urination
• 🧠 Additional symptoms: weight loss, lethargy, unusual coat, poor appetite

Early intervention can identify manageable conditions like PPID or help adjust feed to reduce strain on the kidneys. 🧬

6. How Vets Diagnose Polydipsia Causes 🧬

Expect a thorough veterinary exam to include:

• 🧪 Blood work (BUN, creatinine, glucose, ACTH)
• 💧 Urinalysis (specific gravity, protein, glucose)
• 📈 History of feed, water intake, supplements
• 📊 Measurement of exact water intake over 24 hours

In some cases, hormone testing (for PPID) or kidney function panels are required. 🧠

7. Management Tips for Excessive Drinkers 💡

After ruling out medical causes, some management steps can help:

• ⏱️ Monitor water intake daily—especially in stall settings
• 🥕 Check feed for excessive salt or protein content
• 🌾 Offer consistent forage to stabilize digestion and thirst
• 🧂 Provide free-choice salt blocks, not mixed into feed unless needed
• 💧 Ensure fresh, clean water at all times—but note abnormal changes

8. Prevention and Routine Monitoring ✅

Keeping track of water intake is just as important as feed tracking. Try these practices:

• 📒 Log daily water bucket fill levels
• 📷 Use automatic waterer meters if available
• 🧽 Check bedding for wetness during stall cleaning
• 🌞 Adjust expectations in hot weather—but still watch for excess

9. Summary Chart: Water Intake Guidelines 📋

10. Final Thoughts from Dr Duncan Houston 💬

Water is life—but too much can be a red flag. Know your horse’s baseline intake, and don’t ignore consistent increases. Polydipsia could signal serious underlying conditions like kidney dysfunction or Cushing’s disease. 🧠🩺

If you’re concerned about how much your horse drinks, talk to your vet. For ongoing guidance and access to expert advice, visit AskAVet.com or download the Ask A Vet app 📲 to stay ahead of your horse’s health.

— Dr Duncan Houston, BVSc