Your dog’s health is a delicate balance.
Calcium is an essential nutrient for bone development and health, muscle function, and other critical processes, but too much can be harmful. It may also be the first sign of an underlying disease.
If your dog’s blood work results indicate high calcium levels (hypercalcemia), it’s natural to feel worried and want to help. This article provides practical, vet-supported tips on how to lower calcium levels in dogs naturally as a complement to your veterinarian’s recommendations and treatment plan.
What is hypercalcemia in dogs?
Hypercalcemia refers to excess calcium in your dog’s bloodstream.
While some calcium is stored in the bones or bound to other molecules, the rest circulates in the blood. This is known as ionized calcium. In a healthy dog, blood calcium levels are typically controlled by:
- Parathyroid hormone (PTH) – From the parathyroid glands
- Calcitonin – Produced by the thyroid gland
- Vitamin D (calcitriol) – From the diet
- Kidneys – Remove excess calcium from the blood
But certain diseases and conditions may disrupt this natural balance, leading to increased blood calcium levels.
Without treatment, hypercalcemic dogs may suffer from renal failure (kidney disease), cardiac arrhythmias, seizures, and other serious complications.
Hypercalcemia itself is not a diagnosis, but a symptom of a larger problem. Your veterinarian will recommend additional testing to identify and address what’s causing your dog’s elevated calcium.
The importance of calcium in dogs
Calcium is a critical mineral that plays a vital role in many parts of canine health, including:
- Skeletal structure — Calcium helps build and maintain strong bones and teeth.
- Muscle contractions — Calcium supports normal mobility, plus heart and nervous system function.
- Enzyme activity — Calcium assists with chemical reactions that keep the body running smoothly.
Highs, lows, and ratios
Remember what we said about balance? Here’s a simplified explanation of why it matters:
- Too low — A lack of calcium (hypocalemia) may cause bone loss and dental problems.
- Too high — Excessive calcium may disrupt kidney, musculoskeletal, and nervous system function.
- Ratio to phosphorus — In addition to achieving an appropriate level, calcium must maintain a proper ratio with the nutrient phosphorus to ensure bone health, proper energy, and metabolism. According to the Association of American Feed Control Officials (AAFCO), the minimum correct ratio is 1:1, and the maximum is 2:1.
Now, let’s take a closer look at this nutrient tightrope and how your observations and actions can support your dog’s health.
How much calcium do dogs need?
Now that you know the right amount matters, let’s define what that looks like.
The table below summarizes the AFFCO-recommended calcium and phosphorus levels for adult dogs and growing puppies. These values apply to complete and balanced canine diets, such as JustFoodForDogs.
| Life Stage | Calcium Minimum (% of DM) | Phosphorus Minimum (% of DM) | Recommended Ca:P Ratio |
| Adults (Maintenance) | 0.5% | 0.4% | 1 : 1 |
| Puppies (Growth & Reproduction) | 1.2% | 1.0% | 1 : 1 |
While conditions like cancer (malignancy) and kidney disease (renal failure) may be common causes of elevated calcium in dogs, their diet may also play a role. This is especially true for raw food and homemade diets, which may lack appropriate ratios or include excessive calcium supplementation (hypervitaminosis). If you prepare your dog’s food at home, ensure the right nutrient balance (and your peace of mind) with vet-developed nutrient blends or recipes.
What elevated calcium means for long-term health
If a dog has elevated blood calcium levels, it means they have too much calcium circulating through their system. High calcium may affect muscles, nerves, and kidney function. This change can be subtle at first, so you may not notice any abnormalities.
Left untreated, hypercalcemia may cause serious health problems, including permanent organ damage. Diagnosis and treatment of its underlying cause, along with regular monitoring and guidance from your veterinarian, are essential.
Symptoms of hypercalcemia in dogs
Because calcium affects many parts of the body, high levels can cause a variety of symptoms, such as:
- Increased thirst (polydipsia) and urination (polyuria) — These increase as kidneys work harder to flush out excess calcium.
- Appetite loss — High calcium disrupts the body’s signals, including hunger.
- Vomiting or constipation — High calcium can irritate the stomach and slow digestion.
- Muscle weakness or tremors — Too much calcium affects normal contractions.
- Lethargy — Poor muscle and nerve function leaves dogs low on energy.
- Kidney or bladder stones — The body deposits excess calcium in these organs.
- Behavior changes (restlessness, confusion) — Abnormalities in the nervous system can affect how dogs feel and think.
- Enlarged lymph nodes — This can happen if lymphoma is the primary cause.
If your dog shows one or more symptoms of hypercalcemia in dogs, seek veterinary care. Spotting hypercalcemia early gives your veterinarian more time to determine its cause and provide targeted treatment before permanent damage occurs.
What may contribute to elevated calcium in dogs?
So why do calcium levels get out of control? Common causes of hypercalcemia in dogs may include:
- Cancer (neoplasia) — Certain cancers may cause a release of excess calcium. Also known as hypercalcemia of malignancy, common causes include lymphoma and anal gland adenocarcinoma.
- Hyperparathyroidism — The parathyroid gland, located near the thyroid gland, can become overactive and raise blood calcium. Primary hyperparathyroidism may be caused by a benign tumor.
- Hypoadrenocorticism (Addison’s disease) — Underactive adrenal glands can affect the body’s vitamin and mineral balance.
- Chronic kidney disease — Kidney failure may affect the kidneys’ ability to filter out excess calcium.
- Dehydration — Dehydration strains the kidneys and causes an electrolyte imbalance.
Hypercalcemia may also be linked to diet. This includes:
- Vitamin D toxicity or oversupplementation — Supplemental vitamin D or incorrectly adding too much to your dog’s home-cooked diet; this is also known as hypervitaminosis
- Too much calcium in homemade diets — Inaccurate calcium/phosphorus ratios or oversupplementation of calcium
Note: The information in this article is for educational purposes only and should not be used as a substitute for veterinary guidance, diagnosis, or treatment. Hypercalcemia is a potentially dangerous symptom that requires professional medical diagnosis and care.
How to support a dog with high calcium levels at home
Before we dive into at-home strategies, remember that veterinary care is the cornerstone of diagnosing and addressing hypercalcemia in dogs. Understanding typical veterinary treatment can help you see how home care supports, but doesn’t replace, professional veterinary treatment and care.
How vets treat high calcium in dogs
Treatment for high calcium in dogs depends on the underlying cause and how high their calcium level is. As your veterinarian works to determine the cause, they will use different methods to lower your dog’s calcium levels, including:
- Intravenous (IV) fluids — Added hydration helps flush excess calcium from the body via the kidneys.
- Medication — Various medications can also help lower levels by reducing intestinal calcium absorption and, once a diagnosis is established, by addressing underlying conditions.
- Surgery — Dogs with a diagnosis of hyperparathyroidism or malignancy (cancer) often require surgery to remove the parathyroid gland or tumor and stop calcium production.
Once your dog’s calcium is stabilized and any underlying diagnosis is under control, the following at-home care tasks can help maintain overall health and comfort.
Supporting health at home
Supporting your hypercalcemic dog at home includes prioritizing healthy, balanced nutrition and appropriate hydration. Seek veterinary approval before adding these to your pet’s routine.
A vet-approved plan to lower calcium levels in dogs naturally may include:
- Feeding a complete and balanced diet with the correct calcium-to-phosphorus ratio — Fresh diets provide easily digestible, whole-food nutrition that is correctly balanced for dogs and contains natural moisture from meat and vegetables for added hydration. Look for a diet that is complete and balanced to ensure a precise calcium-to-phosphorus ratio.
- Avoiding calcium or vitamin D supplements unless prescribed — Supplementation is unnecessary when your dog eats a complete and balanced diet. Additionally, if your dog’s high calcium is caused by poor kidney function, any extra calcium only increases the strain.
- Increasing hydration through fresh water and moisture-rich meals — Water is vital to every process in your dog’s body, especially the kidneys, which filter excess calcium. Dehydration can worsen hypercalcemia, so try adding water to your dog’s meals, ensuring continuous access to fresh drinking water, and increasing moisture with fresh diets.
- Supporting digestive health with fiber-rich foods — Fiber nourishes your dog’s gut, regulates digestion, and promotes a healthy microbiome. Adding leafy greens, broccoli, pumpkin, or sweet potato to your dog’s bowl helps their body absorb nutrients more effectively. Plus, it tastes good!
- Choosing vet-formulated homemade diets to prevent nutrient excess — Homemade diets may seem like the healthy way to feed your dog, but without an appropriate balance of vitamins and minerals, they can lead to hypervitaminosis and other health abnormalities. Vet-formulated diets meet AAFCO standards and contain the right amount of key nutrients.
- Promoting kidney health through balanced protein and low-sodium meals — Your dog’s kidneys work 24/7 to flush out excess calcium, by-products, and waste. Ease their workload and support healthy function with diets that contain moderate protein and low sodium, plus added moisture to prevent dehydration.
- Using vet-formulated Nutrient Blends for precise home-cooked balance — Cooking for your dog lets you control what goes into their bowl, but it can be tricky to know if your recipe includes all the right vitamins and minerals. Our DIY Nutrient Blends provide the perfect balance in every bite.
Give your dog tailored nutritional support
Achieving long-term calcium balance and recovery from hypercalcemia isn’t a quick fix. You can’t solve it with a one-size-fits-all diet. It requires ongoing effort, attention, and care. Personalized, vet-formulated nutrition, when used under veterinary guidance, may support your dog’s course of treatment and minimize the risk of future imbalance or elevations.
Interested in learning more about how nutrition can help manage your dog’s calcium levels and support long-term wellness? Explore our complete range of personalized feeding options, including our Vet-Prescribed Meals and Custom Diets.
This content is for informational use only and does not replace professional nutrition and/or medical advice, diagnosis, or treatment. It is not a substitute for specific nutrition and/or medical recommendations. Please talk with your veterinarian about any questions or concerns.
“Calcium Disorders.” n.d. The College of Veterinary Medicine at Michigan State University. https://cvm.msu.edu/vdl/laboratory-sections/endocrinology/calcium-disorders-1.
Kruger, John M, Carl A Osborne, Raymond F Nachreiner, and Kent R Refsal. 1996. “Hypercalcemia and Renal Failure” 26 (6): 1417–45. https://doi.org/10.1016/s0195-5616(96)50135-x.
