Vet’s 2025 Guide to Hypomagnesemia in Dogs 🩺🐾 

By Dr. Duncan Houston BVSc

Hypomagnesemia (low blood magnesium) is common in sick dogs, particularly those in the ICU or with critical illness. Though often overlooked, it can cause serious neuromuscular, cardiac, and metabolic issues. In this 2025 guide, we'll explore causes, symptoms, diagnostic methods, treatments, and long-term care strategies—integrating telehealth support with Ask A Vet. 🐶✨

1️⃣ Why Magnesium Matters

It’s essential for over 300 biochemical processes, including muscle and nerve function, heart rhythm, energy production, immune response, and bone strength.

2️⃣ Common Causes in Dogs

• Chronic diarrhea, malabsorption, or starvation.
• Pancreatic, liver, kidney, heart, or metabolic diseases and sepsis.
• Medications: diuretics, some anti-cancer drugs, insulin, IV fluids lacking Mg.
• Endocrine disorders: diabetes, thyroid, or parathyroid disease.

3️⃣ Who is at Risk?

Critically ill dogs—39–46% in ICU—plus breeds like Collies and German Shepherds show higher rates.

4️⃣ Signs to Watch For

• Muscle weakness, trembling, tremors, ataxia, tetany.
• Overactive reflexes, seizures, and confusion.
• Cardiac arrhythmias—including ventricular tachycardia, torsades—especially in the ICU.
• Poor appetite, depression, and possible coma in severe cases.
• Often occurs with hypokalemia or hypocalcemia.

5️⃣ Diagnosing Hypomagnesemia

• Blood magnesium levels: serum total and ideally ionized magnesium.
• Electrolyte panels: simultaneously assess calcium and potassium.
• ECG monitoring: to detect arrhythmias during treatment.
• Assess underlying disease: CBC, chemistry, urinalysis.

6️⃣ Treatment Strategies 🛠️

🧪 Mild to Moderate Cases

• Oral magnesium supplements or electrolyte solutions.
• Treatment of underlying condition (e.g., diarrhea, endocrine, kidney disease).
• Monitor concurrent calcium/potassium levels.

💉 Severe or Symptomatic Cases

• IV magnesium sulfate infusion (50–150 mg/kg/day).
• Slow infusion for cardiac safety, with ECG monitoring.
• Treat hypokalemia and hypocalcemia concurrently.

7️⃣ Monitoring & Prognosis

• Daily magnesium and ECG checks during acute therapy.
• Reassessment of underlying diseases and adjustment of therapies.
• Post-recovery diet should be balanced; healthy dogs rarely require long-term supplementation.
• Critical cases: prognosis depends on the underlying disease and timely correction.

8️⃣ Supportive Care & Brand Integrations

• Ask A Vet: telehealth for monitoring, ECG review, electrolyte management.

9️⃣ When to Contact the Vet Immediately

• Muscle tremors, tetany, twitching, or seizures.
• Signs of heart irregularity or collapse symptoms.
• Persistent vomiting or diarrhea causing electrolyte loss.
• No improvement or worsening during supplementation.

🔟 Final Thoughts

Hypomagnesemia is a common and significant electrolyte imbalance in ill dogs, with serious neuromuscular and cardiac complications. Early recognition, precise diagnostics, balanced supplementation, and treatment of the underlying cause—paired with telehealth support and comfort tools—can lead to full recovery in most cases by 2025. 📈🐾

Need help monitoring levels or adjusting care? Visit AskAVet.com, download the Ask A Vet app, and support your pet's journey. 🐶📱