🩺 Equine Nephritis (Kidney Inflammation): A Vet’s 2025 Guide | Dr Duncan Houston BVSc

Meta description: Learn about pyelonephritis, interstitial nephritis, glomerulonephritis in horses—recognise signs, diagnostics, treatment, prevention & Ask A Vet’s tailored care.

1. 🧬 What is Nephritis?

Nephritis refers to inflammation of one or both kidneys. In horses, it may be:

• Pyelonephritis: Infection ascending from bladders or urinary tract.
• Interstitial nephritis: Inflammation of renal interstitium, often bacterial toxin or immune-related :contentReference[oaicite:3]{index=3}.
• Glomerulonephritis: Immune-complex inflammation of glomeruli—rare, but serious :contentReference[oaicite:4]{index=4}.

Though uncommon, healthy adult horses are typically resistant to kidney disorders, yet when nephritis occurs it can significantly impair urinary and metabolic function :contentReference[oaicite:5]{index=5}.

2. ⚠️ Why Early Detection Matters

The equine kidney filters blood, regulates fluid balance, electrolytes, and rids toxins. Damage from nephritis may cause renal failure, electrolyte imbalances, hypertension, edema, and weight loss. Prompt management improves outcomes :contentReference[oaicite:6]{index=6}.

3. 🔍 Clinical Signs

• Lethargy, reduced appetite, weight loss :contentReference[oaicite:7]{index=7}
• Fever, flank pain, discomfort on palpation :contentReference[oaicite:8]{index=8}
• Polyuria/polydipsia (increased urination and drinking) :contentReference[oaicite:9]{index=9}
• Edema—ventral or limb swelling :contentReference[oaicite:10]{index=10}
• Abnormal urine—blood, pus or foul odor :contentReference[oaicite:11]{index=11}
• Oral ulcers or dental changes due to uremia :contentReference[oaicite:12]{index=12}

4. 🧪 Diagnostic Approach

Thorough evaluation is essential:

• History & Exam: Signs of urinary or systemic disease.
• Blood tests: Elevated urea, creatinine, abnormal electrolytes :contentReference[oaicite:13]{index=13}.
• Urinalysis & culture: Identifies infection, proteinuria, cellular casts :contentReference[oaicite:14]{index=14}.
• Ultrasound/X-ray: Detects kidney abscesses, stones, structural changes :contentReference[oaicite:15]{index=15}.
• Biopsy: Rare but definitive for glomerulonephritis :contentReference[oaicite:16]{index=16}.

5. 🛠️ Medical Treatment & Supportive Care

Treatment depends on type:

• Antibiotics: Long‐term broad-spectrum or culture‐guided for pyelonephritis/interstitial nephritis :contentReference[oaicite:17]{index=17}.
• IV fluids: Support renal perfusion, correct dehydration/electrolyte loss :contentReference[oaicite:18]{index=18}.
• Electrolyte supplementation: Monitor sodium, potassium to maintain balance :contentReference[oaicite:19]{index=19}.
• Anti-inflammatory & pain relief: NSAIDs carefully balanced against renal risk.
• Treat underlying causes: Remove bladder stones, relieve urinary obstructions :contentReference[oaicite:20]{index=20}.
• Severe cases: Hospitalisation, possible surgical drainage, dialysis-like therapy in rare cases :contentReference[oaicite:21]{index=21}.

6. 🌱 Chronic Nephritis & Long-Term Management

Chronic cases may lead to ongoing renal damage:

• Weight loss, chronic PU/PD, edema :contentReference[oaicite:22]{index=22}
• Reduced kidney mass visible on post-mortem :contentReference[oaicite:23]{index=23}
• Supportive care only—no curative treatment for chronic kidney disease :contentReference[oaicite:24]{index=24}
• Focus on nutrition (low protein, high energy), hydration, regular monitoring :contentReference[oaicite:25]{index=25}

7. 🛡️ Prevention & Risk Reduction

• Treat UTIs early, especially in mares/foals :contentReference[oaicite:26]{index=26}.
• Limit nephrotoxic drugs (NSAIDs, aminoglycosides) :contentReference[oaicite:27]{index=27}.
• Ensure hydration at all times—especially in transport, heat or illness.
• Keep bladder and urinary tract clear; remove stones or obstructions promptly.
• Regular health screening for older horses—blood & urine tests.

8. 💬 Ask A Vet Tailored Support

• 📋 Custom monitoring plans—bloodwork schedules, urinalysis, fluid therapy protocols.
• 📸 Remote review of hydration status, edema, urine color/volume.
• 📆 Med reminders for antibiotic courses, follow-up tests.
• 🎓 Webinars: “Avoiding Nephrotoxic Drugs,” “Hydration Strategies,” “CKD Nutrition in Horses.”

9. ❓ FAQs

Can horses recover fully from pyelonephritis?

Yes—if treated early with appropriate antibiotics and care; kidney function often returns. Chronic cases carry guarded prognosis :contentReference[oaicite:28]{index=28}.

Is chronic kidney disease common?

Rare in horses (~0.2%), but often diagnosed late. Chronic nephritis can last months to years with supportive care :contentReference[oaicite:29]{index=29}.

What diet helps CKD horses?

Feed low-protein, high-energy forage; monitor BUN:creatinine. Avoid alfalfa if renal dysfunction is present :contentReference[oaicite:30]{index=30}.

When should I call the vet?

Any weight loss, increased drinking/urination, edema, fever or pain warrants prompt veterinary evaluation and diagnostics.

10. ✅ Final Takeaway

Nephritis in horses—whether acute, infectious, or chronic—is serious but often treatable. Early diagnosis, targeted antibiotic therapy, fluid and electrolyte support, and vigilant follow-up are key. Nutritional and management strategies help support chronic cases. Ask A Vet can guide you with custom monitoring, treatment reminders, hydration protocols and education—helping your horse thrive in 2025 and beyond.