If your dog is experiencing hypercalcemia, it is important to get them the treatment they need as soon as possible. Hypercalcemia in dogs can be a serious condition and left untreated, it can affect multiple body systems such as the kidneys, heart, and gastrointestinal system. In this blog post, we will discuss the causes, symptoms, and treatment of hypercalcemia in dogs.

What is hypercalcemia in dogs?

Hypercalcemia in dogs is a condition characterized by elevated calcium levels in the blood. It occurs when the mechanisms that regulate the calcium levels in the body are disrupted, leading to an accumulation of calcium in the extracellular fluid.

What are the causes of hypercalcemia in dogs?

There are many different things that can contribute to hypercalcemia in dogs. Some of the most common include:

  1. Cancer/Hypercalcemia of malignancy: Tumors that produce PTHrP (parathyroid hormone-related protein) can lead to hypercalcemia by stimulating the release of calcium from the bone. Anal gland malignant tumors and lymphoma are common causes of hypercalcemia in dogs.
  2. Kidney disease: Kidney disease can cause hypercalcemia by reducing the excretion of calcium in the urine.
  3. Vitamin D toxicity: Vitamin D is necessary for calcium absorption from the gut, but too much vitamin D can lead to hypercalcemia. The most common cause of vitamin D toxicity in dogs is secondary to some rodenticide agents.
  4. Addison's disease: The underlying cause of hypercalcemia in dogs with Addison's disease (hypoadrenocorticism) is unknown, and it usually goes away on its own after the dog has been treated for Addison's disease.

What are the symptoms of hypercalcemia in dogs?

The symptoms of hypercalcemia in dogs vary depending on the severity of the condition and some dogs with hypercalcemia may be asymptomatic. Some of the most common symptoms include:

  • Lethargy
  • Anorexia
  • Seizures
  • Vomiting
  • Diarrhea
  • Muscle weakness and twitching
  • Cardiac arrhythmias
  • Excessive thirst and urination

If you notice any of these symptoms in your dog, it is important to take them to the vet as soon as possible for an examination. Hypercalcemia can be a serious condition and left untreated, it can lead to organ damage or failure.

How is hypercalcemia in dogs diagnosed?

If your veterinarian suspects that your dog has hypercalcemia, they will likely run some blood tests to confirm the diagnosis. Some of the tests that may be run include a complete blood count, biochemistry panel, and ionized calcium test. A chest x-ray and/or abdominal imaging may also be performed to check for evidence of tumors or other abnormalities.

How is hypercalcemia in dogs treated?

The treatment for hypercalcemia in dogs will vary and is focused depending on the underlying cause. If a dog is suffering from hypercalcemia, dehydration, azotemia (elevated renal toxins in the bloodstream), cardiac arrhythmias, or neurologic dysfunction, it may require immediate medical therapy.

Supportive therapy may include:

Fluid therapy: This is usually the first line of treatment for hypercalcemia in dogs as it helps to keep them hydrated and also aids in the excretion of calcium in the urine.

Glucocorticoids: These are corticosteroid drugs such as prednisone that can help to reduce bone reabsorption of calcium.

Bisphosphonates: These drugs are used to reduce bone turnover and can be helpful in the treatment of hypercalcemia caused by cancer.

Calcitonin: This is a hormone that helps to reduce calcium levels in the body

Diuretics: These drugs help to increase the amount of calcium excreted in the urine and are often used in combination with other treatments.

Monitoring response to therapy through physical examinations and laboratory tests is crucial. Depending on the severity of the hypercalcemia, serum ionized calcium levels can be monitored every few days to every 3-4 weeks. Once calcium levels have normalized, monitoring can be done every 3-6 months.

What is the prognosis for dogs with hypercalcemia?

The prognosis of hypercalcemia in dogs depends on the underlying cause and the success of therapy. Uncontrolled hypercalcemia can lead to renal failure, urolithiasis, cardiac arrhythmias, urinary tract infections, chronic gastrointestinal signs, and neuromuscular abnormalities.


Hypercalcemia in dogs is a condition that can be caused by a variety of factors, including cancer, kidney disease, and vitamin D toxicity. Symptoms of hypercalcemia include lethargy, seizures, vomiting, and diarrhea. If left untreated, hypercalcemia can lead to organ damage or failure. Treatment for hypercalcemia may include fluid therapy, glucocorticoids, bisphosphonates, calcitonin injections and/or diuretics. With early diagnosis and treatment, the prognosis for hypercalcemic dogs is generally good. Please reach out to your veterinarian if you have any further questions about hypercalcemia in dogs.