Can dogs overdose on magnesium? A Complete Guide

Causes of Excess Magnesium in the Blood in Dogs

The following conditions are often associated with hypermagnesemia.

  • Kidney failure
  • Hypoadrenocorticism (Addison’s disease)
  • Hyperparathyroidism
  • Hypothyroidism
  • Overdose of magnesium containing medication
  • Laxatives, antacids, cathartics
  • Pericardial effusion (fluid in the heart)
  • Hemolysis (bursting red blood cells)
  • Injury or necrosis of large amounts of muscle tissue
  • What is Excess Magnesium in the Blood?

    Magnesium is very important positive ion that is vital for many cellular processes. The majority of the magnesium in the body is found inside the cells, especially the bones, but about 1 % circulates in the blood stream, either as an active ion (55%) or bound to proteins and other complex molecules. Excess magnesium in the blood, called hypermagnesemia, can be a very serious problem since magnesium limits the function of calcium ions. This leads to muscle weakness, abnormal heart rhythms, and eventually respiratory paralysis and cardiac arrest. Magnesium is normally excreted by the kidneys. In dogs, normal kidney function will maintain a typical magnesium serum concentration below 2.5 mg/dl, even if high levels of magnesium are ingested. Severe renal failure is the most common reason for blood magnesium levels to rise. This is frequently a problem if dogs with kidney failure receive IV fluids high in magnesium. Some endocrine imbalances or a pericardial effusion (fluid inside the heart cavity) can also cause hypermagnesemia. Magnesium levels may rise temporarily from an overdose of a magnesium containing medication, like laxatives or antacids, or due to blood or muscle cell destruction that liberates a large amount of intracellular magnesium into the blood. Hypermagnesemia is less common in dogs than magnesium deficiency, but when it does occur, it can be associated with life-threatening problems. Administration of IV fluids and other electrolytes can correct the immediate symptoms, however, dogs with kidney failure or heart failure still often end up being euthanized.

    About 1% of the magnesium in the body circulates in the blood as a positive ion. Magnesium works in combination with other electrolytes to manage many cellular processes. Excess magnesium, called hypermagnesemia, upsets the normal balance between ions and causes serious life-threatening symptoms.

    Excess Magnesium in the Blood Average Cost

    From 49 quotes ranging from $500 – $5,000

    Symptoms of Excess Magnesium in the Blood in Dogs

    Mild hypermagnesemia can often be asymptomatic, but very high levels will present serious life-threatening symptoms that should be treated as an emergency.

  • Muscle weakness
  • Hypotension
  • Decreased tendon reflexes
  • Difficulty breathing
  • Abnormal heart rhythm
  • Shock or coma
  • Types

    The veterinarian will categorize your dog’s hypermagnesemia based on its severity.

  • Mild – ionized serum level 2.5-4 mg/dl
  • Severe – ionized serum level > 4mg/dl- this is when most clinical symptoms appear
  • Magnesium Toxicity

    Hypermagnesemia leads to the progressive loss of respiratory, cardiovascular, nervous, and muscle functions — all of which can be fatal in the dog. Other symptoms associated with this issue include: Nausea. Vomiting.