Excess Calcium in the Blood in Dogs

PetMD Editorial

Published Sep. 11, 2008

Hypercalcemia in Dogs

Behind the thyroid gland in the neck, there lie four parathyroid glands which secrete the hormone the body needs to regulate calcium and phosphorus. Parathyroid hormone and vitamin D interactions work to release calcium from the bones, gut, and kidneys for deposit into the bloodstream. When these interactions are disturbed, or when cancerous cells secrete hormones that interfere with calcium regulation, hypercalcemia can result. Hypercalcemia is characterized by an abnormally high amount of calcium in the blood. A dog is considered hypercalcemic when its total serum calcium is greater than 11.5 mg/dL.

Symptoms and Types

Increased urination
Increased thirst
Lack of appetite (anorexia)
Vomiting
Decreased gastrointestinal function
Constipation
Lack of energy/fatigue/lethargy
Confusion
Depression
Enlarged lymph nodes (swelling in neck)
Bladder stones
Hypertension
Stupor and coma in severe cases

Causes

Abnormal or over functioning of the parathyroid gland (hyperparathyroidism)
Cancer or tumors
Bone deteriorating diseases
Kidney failure - sudden or long-term
Under-functioning adrenal glands
Vitamin D poisoning: from rodenticides, plants, or food (supplements included)
Aluminum toxicity

Diagnosis

Your veterinarian will perform a complete physical exam, with a blood chemistry profile, a complete blood count, and a urinalysis. While a high serum is crucial to the diagnosis of hypercalcemia, the results of the other tests will help to indicate the origin of the hypercalcemia.

Radiograph and ultrasound imaging can also be used for diagnosing underlying conditions, such as kidney disease, bladder stones, or cancer. Fine needle aspirates (liquids) from the lymph nodes and bone marrow can be used for diagnoses of lymphoma, or cancer of the blood.

Treatment

If your dog has been diagnosed with hypercalcemia, your veterinarian will very likely want to hospitalize it for fluid therapy. Once the primary disease is diagnosed, your dog will be given the appropriate medication(s). Your doctor will continue to check your dog’s serum calcium twice a day during its stay at the veterinary clinic, until calcium levels have returned to normal.