The role of nutrition in treating low calcium levels in dogs

Hypocalcemia, a low blood calcium level, is a clinical finding in blood work that can indicate an underlying health problem. Dog owners who learn their pet is hypocalcemic may naturally assume they need to change their dog’s diet or start giving calcium supplements. However, successfully treating low calcium blood levels in dogs focuses on finding the cause of the imbalance and addressing that. Before you give your dog a calcium supplement, it’s best to talk to a vet about:

• The causes of low blood calcium levels in dogs
• Treating hypocalcemia in dogs
• The role of nutrition in treating dogs with low calcium levels

“It’s a common misconception that low calcium means a dog just needs more of it in their food,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “Regardless of calcium intake, the body maintains calcium levels within a narrow range through complex processes. The issue is usually with calcium regulation rather than with the diet.”

Calcium supplementation isn’t always straightforward. Supplements must maintain the correct balance with other nutrients to be effective. Inappropriately supplementing a dog’s diet with calcium may disrupt this balance and make things worse. If you have questions about your dog’s calcium intake or how to manage a condition that affects calcium levels, a virtual vet appointment is a convenient way to get professional guidance. Online visits make it easy to check in with your vet and stay on top of your dog’s care plan.

Hypocalcemia is a clinical finding of abnormally low blood calcium levels. It’s a change seen on blood work, not a disease itself, and it can indicate an underlying health problem. Because a low blood calcium level doesn’t usually indicate a deficiency in the diet, nutrition doesn’t play a big role in the treatment of hypocalcemia.

Calcium is an important mineral for multiple functions within the body, including:

• Bone health and skeletal development
• Muscle contraction, including the heart and the muscles that move intestinal contents through the digestive tract
• Activation of certain enzymes
• Regulation of the nervous system

The body has mechanisms in place to keep blood calcium levels stable regardless of how much a dog is eating. This ensures that, in healthy dogs, blood calcium levels stay within a specific range even if the amount in the diet fluctuates. When the body needs to raise blood calcium levels, it draws calcium from the bones, where calcium is stored as a mineral, and from the intestines, where dietary calcium enters the body.

The kidneys flush away excess calcium to keep levels balanced in the body. Parathyroid hormone (PTH) and calcitriol (vitamin D) control how calcium is absorbed and removed from the body.

Chronic low blood calcium levels can negatively affect multiple bodily systems, causing symptoms such as:

• Nervousness or agitation
• Drunken walk (ataxia)
• Seizures
• Muscle tension or twitching

It’s important to seek veterinary care any time these symptoms are seen. Hypocalcemia is usually caused by an underlying health issue rather than a problem with the diet, so other clinical signs may be present.

Causes of low blood calcium levels in dogs

The regulation of calcium in the body is complex and involves multiple bodily systems. Because it’s a complex system, there are multiple health issues that can cause hypocalcemia, including:

• Eclampsia
• Primary hypoparathyroidism
• Chronic kidney failure
• Acute pancreatitis
• Ethylene glycol (antifreeze) toxicosis

Hypocalcemia almost always indicates an underlying health problem rather than an issue with the dog’s diet. Successful treatment depends on identifying and managing the root cause.

Most healthy adult dogs that are not pregnant or nursing receive all the calcium they need in a typical, commercially available diet. Pregnant or nursing dogs, growing puppies, and dogs with certain health conditions may be at higher risk for hypocalcemia.

It’s possible but rare for low blood calcium levels to occur due to inappropriately low levels of calcium in the diet or a vitamin D deficiency that leads to poor calcium absorption. This is very rare in dogs, especially in dogs eating a commercially available, well-balanced diet with a statement of nutritional adequacy from the Association of American Feed Control Officials (AAFCO) on the label.

Hypocalcemia is usually identified in one of two ways when a dog has blood work done:

• As part of an emergency presentation with severe symptoms
• As an incidental or secondary finding

In cases of an emergency, a dog with severe hypocalcemia may present with serious clinical signs like tremors, muscle stiffness, facial twitching, restlessness, ataxia, or seizures. Emergency causes of hypocalcemia include eclampsia, acute pancreatitis, or ethylene glycol toxicity. Eclampsia is the most common emergency cause of hypocalcemia in dogs. It occurs most often in small-breed mothers during the peak milk-production period, especially in dogs nursing large litters.

Treatment for emergency hypocalcemia involves administering calcium gluconate through an IV while monitoring the dog’s heart with an ECG. After that, the underlying cause of the hypocalcemia is addressed, such as by treating eclampsia or stabilizing pancreatitis.

In nonemergency cases, hypocalcemia is often discovered during routine or diagnostic blood work in dogs that seem healthy or are showing only mild, vague symptoms. For example, hypocalcemia may be seen in dogs with chronic kidney disease or recurrent gastrointestinal disease. In these cases, treatment focuses on the underlying disease. Because the hypocalcemia itself is not causing severe symptoms, calcium supplementation may not be necessary. Dietary calcium adjustments alone rarely solve the problem because the issue is usually how the body regulates calcium, not how much is consumed.

The role of nutrition in the treatment of hypocalcemia depends on the underlying cause. In the majority of cases, low blood calcium levels aren’t caused by inadequate dietary intake, so dietary changes alone won’t help. Instead, treatment focuses on the primary disease that’s disrupting the body’s ability to regulate calcium. While nutrition can support recovery and long-term balance, it’s rarely the main form of therapy.

Eclampsia (periparturient or postpartum hypocalcemia) is the most common acute cause of hypocalcemia in dogs. In order to stabilize the patient, low blood calcium levels need to be immediately corrected with intravenously administered calcium gluconate. After the dog is stabilized, a diet formulated for growth or lactation may be recommended to safely increase dietary calcium.

Depending on the size of the litter and the condition of the mother, a vet may prescribe a temporary calcium supplement during lactation. Other methods of calcium supplementation aren’t usually recommended because they can make hypocalcemia worse by suppressing parathyroid hormone (PTH). Nutritional support also includes ensuring the mother is getting enough calories to support milk production and reducing calcium demand by weaning the puppies as soon as they’re old enough.

For dogs with chronic or mild hypocalcemia, such as those with chronic kidney disease (CKD), stabilization isn’t usually needed. The primary issue for dogs with CKD is a reduced ability of the kidneys to activate vitamin D and regulate calcium and phosphorus excretion.

Nutritional management plays a major supportive role in controlling the secondary effects of kidney disease like hypocalcemia. Therapeutic diets for chronic renal disease are formulated to provide a safe balance of calcium, vitamin D, and phosphorus. While diet helps to regulate CKD, it doesn't directly correct hypocalcemia. Calcium supplements are usually only prescribed for dogs with CKD if secondary hyperparathyroidism develops, disrupting the balance of calcium and phosphorus.

Does my dog need calcium supplements?

It’s important to talk to a veterinarian before giving your dog calcium supplements. The majority of healthy dogs eating an appropriate diet do not need any form of calcium supplementation, and the right ratio of calcium, vitamin D, and phosphorus is just as important as getting enough calcium. Supplementing calcium can upset this ratio and cause other health problems, which is one reason why calcium, phosphorus, or vitamin D supplementation should only be given with veterinary supervision. If you think your dog may need calcium supplements, talk to a vet first, not only to confirm the necessity but also to get advice on choosing a safe product.

All dogs need a healthy, well-balanced diet to provide adequate nutrition, including the right amount of calcium and other nutrients. Choose a diet with the AAFCO seal of nutritional adequacy on the label and follow the feeding guidelines on the package based on your dog’s body weight. Puppies, pregnant or nursing dogs, and dogs with underlying health issues may benefit from a special diet formulated for their life stage or specific health condition. These diets may have additional calcium, vitamin D, or phosphorus in them to ensure your dog is receiving the right amount of each nutrient.

An online vet is a convenient resource to discuss your dog’s dietary needs with a veterinary professional. For dogs being treated for hypocalcemia, virtual vet appointments can simplify check-ins and communication with your vet.

What causes hypocalcemia in dogs?

Hypocalcemia, or a low blood calcium level, is usually caused by an underlying health issue in dogs rather than a poor diet. Metabolic conditions, such as kidney disease, gastrointestinal conditions affecting nutrient absorption, eclampsia, and other health issues, can lead to hypocalcemia in dogs.

How do you treat calcium deficiency in dogs?

Hypocalcemia, or a low blood calcium level, is treated by addressing the underlying medical issue that’s causing it. Hypocalcemia is usually due to an underlying health condition rather than a deficiency in the diet, so dietary modification or adding an oral calcium supplement to your dog’s diet usually doesn’t help and can even make things worse.

Can diet cause hypocalcemia in dogs?

It’s uncommon for diet alone to cause low blood calcium in dogs. Most cases of hypocalcemia are due to underlying health problems, not nutritional deficiencies. However, a poorly balanced or homemade diet that doesn’t provide enough calcium or the correct ratio of calcium, phosphorus, and vitamin D can eventually lead to low calcium levels. Vitamin D deficiency can also contribute, since this vitamin helps the body absorb calcium from food. Feeding a complete and balanced commercial diet that meets AAFCO nutrient standards prevents dietary calcium deficiency in healthy dogs.

Disclaimer: This article, its content, and its related references do not constitute veterinary advice and should not be considered a substitute for veterinary care. If your pet is showing any symptoms that could indicate a medical emergency, please seek immediate emergency care.