Hypocalcemia in Dogs
If your canine companion exhibits lower-than-normal levels of calcium in its bloodstream, it is experiencing a medical condition called hypocalcemia. Calcium is pivotal in essential bodily processes such as bone and teeth development, blood coagulation, lactation, muscle movement, cardiac function, vision, and the metabolism of hormones and enzymes. Consequently, calcium deficiency represents a grave concern demanding prompt intervention.
Symptoms and Types
The symptoms exhibited may vary based on the root cause and seriousness of the issue. Nonetheless, some prevalent symptoms encompass:
- Muscle spasms and tremors
- Difficulty coordinating movements or stiff walking
- Heavy panting
- Rubbing the face against surfaces
- Nausea and vomiting
- Loss of appetite
- Elevated body temperature
- Fatigue
- In mild instances, symptoms might not manifest until the calcium levels plummet significantly below the normal threshold of 6.7 mg/dL.
Causes
Albumin, a protein present in the blood, plays a crucial role in binding a significant fraction of calcium along with free calcium in the bloodstream. When the level of albumin decreases (known as hypoalbuminemia) due to various health conditions, it impacts the total calcium level in the body. Although hypoalbuminemia accounts for over 50 percent of hypocalcemia cases, low calcium levels associated with this condition typically do not manifest any symptoms.
Hypocalcemia can also arise from various other causes:
- Kidney failure, whether acute or chronic.
- Impaired calcium absorption in the gastrointestinal tract.
- Alkalosis, a condition characterized by excessive alkali (base) in body fluids.
- Hypoparathyroidism, which involves insufficient secretion of parathyroid hormone leading to abnormally low calcium levels in the blood.
- Hypoparathyroidism secondary to surgical removal of the thyroid gland (thyroidectomy).
- Nutritional secondary hyperparathyroidism.
- Oxalate toxicity from substances like lilies, philodendrons, etc.
- Hypomagnesemia, defined by low levels of magnesium in the bloodstream.
- Acute pancreatitis, an inflammation of the pancreas.
- Rickets, a disease occurring in early age due to a deficiency of vitamin D and sunlight, leading to impaired calcium and phosphorus metabolism.
- Puerperal tetany, a clinical neurological syndrome characterized by muscular twitching, cramps, and seizures, associated with calcium deficiency (hypoparathyroidism), vitamin D deficiency, or alkalosis.
- Phosphate-containing enemas used in patients with severe constipation.
- Citrate toxicity in patients who have undergone multiple blood transfusions for other health issues.
Diagnosis
In certain instances, hypocalcemia may appear due to a laboratory error, mistakenly indicating a health issue in your dog when they are actually healthy. To confirm, it’s crucial to provide a detailed history of your dog’s health, symptoms onset, their nature, and any potential incidents that might have triggered the condition. Your veterinarian will conduct a comprehensive physical examination to assess all body systems and evaluate your dog’s overall health. Routine tests, including complete blood count, biochemistry profile, and urinalysis, will offer valuable insights into blood calcium levels and potential causes of hypocalcemia in your dog.
If kidney failure is suspected as the underlying cause of hypocalcemia, a complete blood count may reveal anemia in dogs with chronic kidney failure. Anemia might also be observed in cases of nutrition-related secondary hyperparathyroidism or poor calcium absorption in the intestines.
In instances of infection or inflammation (such as pancreatitis), elevated white blood cell counts may be detected. In dogs with pancreatitis, elevated levels of amylase and lipase enzymes might also be observed. Dogs with hypoalbuminemia (low albumin levels) will show disturbances in calcium levels on the biochemistry profile. Additionally, if alkalosis is causing hypocalcemia, blood gas analysis will reveal elevated carbon dioxide levels in your dog’s blood.
Dogs with kidney failure, ethylene glycol toxicity, or oxalate toxicity may exhibit elevated Blood Urea Nitrogen (BUN) and creatinine levels. Phosphorus imbalances are common in conditions leading to low calcium levels and may present as abnormally high levels in patients with kidney issues, ethylene glycol toxicity, oxalate toxicity, or hypoparathyroidism. High phosphorus levels and hypocalcemia may also be observed in patients using phosphorus-containing enemas for conditions such as constipation. Urinalysis may reveal dilute urine and the presence of glucose in patients with kidney issues or ethylene or oxalate toxicity.
To ascertain if low calcium levels are causing the symptoms, your veterinarian may order further testing to measure the concentration of ionized calcium fractions, the active form of calcium in the blood. In cases of ethylene glycol toxicity, an ethylene glycol test will confirm the toxicity. A blood sample will be drawn from your dog’s vein and sent to the laboratory to determine ethylene glycol levels, which should normally be zero. If hypoparathyroidism is suspected, detailed tests to assess parathyroid gland function will be conducted.
Abdominal radiography may reveal smaller-than-normal kidneys in dogs with chronic kidney failure and enlarged kidneys in animals with ethylene glycol toxicity, oxalate toxicity, or acute kidney failure. Dogs with nutrition-related secondary hypoparathyroidism may exhibit low bone density on bone X-rays.
Treatment
Typically, hypocalcemia is treated by administering calcium supplementation therapy while closely monitoring to avoid potential side effects associated with excess calcium levels. Your veterinarian will also monitor electrocardiogram (EKG) data, as calcium directly impacts the heart, and significant changes in calcium levels can result in abnormal EKG findings.
Following intravenous calcium therapy, your veterinarian may opt to continue calcium supplementation for an extended duration to prevent recurrence. Moreover, severe cases of hypocalcemia may necessitate prolonged hospitalization.
Living and Management
For cases of temporary hypocalcemia, the initial calcium therapy typically resolves the issue. However, if hypocalcemia stems from a serious underlying health condition, further treatment is necessary to prevent future episodes. Hypocalcemia triggered by nutritional deficiencies or childbirth may also warrant ongoing attention.
If your dog’s hypocalcemia is related to nutrition, your veterinarian will provide updated dietary recommendations. In instances where hypocalcemia is associated with childbirth, measures may include temporarily separating the mother from her puppies. During this time, hand nursing of the puppies can be arranged until the mother’s hypocalcemia is effectively managed.