What Are the Causes of High Potassium in Dogs?

By Catherine Troiano

Potassium is an electrolyte that is found in the cells and in the blood of your dog's body. An ideal potassium level is essential for controlling your dog's nerve impulses, brain function and muscle activity. It also plays a vital role in regulating your dog's heart function.

Normal and Abnormal Potassium Level

The normal reference range for a dog's blood potassium level falls between 3.6 and 5.5 mEq/L. When your dog's potassium level dips too low, the condition is referred to as hypokalemia. Conversely, if his potassium level climbs too high, your dog is suffering from hyperkalemia. Your dog's potassium level is determined by performing a blood chemistry profile.

Your dog's kidneys are responsible for filtering wastes from your dog's blood so that they may be expelled from your dog's body when he urinates. Optimal kidney function is vital to maintaining healthy levels of enzymes, minerals and other important substances, including potassium.

Symptoms and Diagnosis of Hyperkalemia

If your dog is experiencing hyperkalemia, he will present with symptoms that may include:

  • Intermittent gastrointestinal symptoms, such as diarrhea and vomiting.
  • Lethargy.
  • Weakness.
  • Collapse.
  • Paralysis in which the limbs cannot move, but they remain flexible.

Hyperkalemia is an emergency condition that requires immediate veterinary intervention. Dogs who are showing signs of hyperkalemia also will develop cardiac arrhythmias, which are disturbances in the heart's rhythm.

Your veterinarian will perform an electrocardiogram on your dog to assess his heart rate and rhythm. He or she will review your dog's medical history and ask questions regarding your dog's recent activities, including drinking and urinating frequencies. Diagnostic tests will include a complete blood count, a blood chemistry profile and a urinalysis. Additional blood tests and radiographs may be ordered to determine the underlying cause of hyperkalemia.

Causes of Hyperkalemia

When your dog's kidneys no longer function optimally, potassium and other wastes build up in your dog's system. Acute anuric, meaning insufficient urine production, and acute oliguric, meaning complete shut down of kidney function, kidney failures are the most frequent causes of hyperkalemia in dogs. Some common causes of acute kidney failure include antifreeze ingestion and leptospirosis infection. Chronic renal failure also can result in hyperkalemia. Additional causes of hyperkalemia in dogs include:

  • Addison's disease, or hypoadrenocorticism, a condition in which a dog has abnormally low levels of corticosteroid hormones.
  • Poorly regulated diabetes in which ketoacidosis is present.
  • Bladder or kidney stones that cause urinary obstruction in males.
  • High blood platelet count.
  • Certain cancers.
  • Severe bacterial infections, such as pyometra, which is a life-threatening uterine infection.
  • An overdose of potassium bromide, which ┬áis commonly used to control seizures.
  • Certain medications, including some antibiotics and cardiac drugs.

A condition known as pseudohyperkalemia is a common finding in cases when the dog is healthy, but excess potassium is leaked from the cells when blood is drawn for laboratory testing. This is considered a false hyperkalemic result, and pseudohyperkalemia tends to occur in the Asian dog breeds, such as the Akita, the shiba inu and the Shar-Pei.

Treatment for Canine Hyperkalemia

The treatment for hyperkalemia includes an immediate reduction in the dog's potassium level, which is accomplished with intravenous sodium chloride fluid therapy, and treatment of the underlying cause. If the underlying cause is ketoacidosis, for example, insulin therapy and other treatment protocols to regulate the patient's diabetes are administered. While the dog is being treated for hyperkalemia, electrocardiograms will be repeated to monitor the dog's cardiac activity, and bloodwork will be repeated to monitor the progress of reversing the dog's hyperkalemic state. Hyperkalemic patients who are left with residual chronic kidney disease may be placed on a low potassium prescription kidney diet.