Elevated Calcium Levels in a Dog: Too Much Calcium in the Blood Is a Diagnosis?

Describing a problem is not an explanation of a problem.

When interpreting your dog’s blood work, don’t hesitate to insist on an explanation of anything out of normal range and what can be the potential reasons for it.

Elevated Calcium Levels in a Dog: Too Much Calcium in the Blood Is a Diagnosis?

Juno’s story

Last week, a friend contacted me, concerned about her dog drinking like there was no tomorrow. Of course, a dog will drink more when it’s hot or when they exercise and play hard. But that wasn’t the case.

He was drinking as if trying to drown himself.

I told my friend she was right to be concerned and that she should see her vet find out what’s causing this. Excessive drinking can be caused by anything from infections, diabetes, Cushing’s disease, Addison’s disease, kidney issues, liver issues … This is serious stuff and it is important to find out what is going on and address it.

Veterinary visit

My friend went to her vet to have the labs done.

The vet told her that her dog has too much calcium in his blood.

She contacted me again, trying to figure out what she should do about it. She contacted ME trying to figure out what she should do about it.

High blood calcium levels in Juno’s blood

The vet told her the adult dog’s blood calcium was high and sent her on her merry way?

It’s time like this when I would pull my hair out if I had any. Blood calcium is highly regulated and the odds that a dog has too much calcium in the blood from having too much of it in their food are minimal. While reducing dietary calcium might help to get the levels down, what about looking for the real reason?

An accurate diagnosis of the underlying cause of a dog’s hypercalcemia is truly important.


There is such a thing as idiopathic hypercalcemia, but that’s only when nobody can figure out the reason, not because there isn’t one.

Unfortunately, the most common cause of high blood calcium is cancer.

There are other major causes, such as hyperparathyroidism, Addison’s disease, kidney disease … One dietary issue which does cause high blood calcium isn’t actually too much calcium in the diet but too much vitamin D or vitamin D toxicity.

In general, high blood calcium levels mean break-down in the regulation, not too much calcium in the food.

A second opinion

I sent my friend back to the vet. A different one.

One that won’t consider high blood calcium a diagnosis, merely a presentation of the actual problem that’s behind it. Not everything that sounds like a diagnosis is one.

The diagnosis

Fortunately, Juno’s second opinion did result in a diagnosis. And, fortunately, Juno did not have cancer or kidney failure. He also did not have idiopathic hypercalcemia. But he was diagnosed with Addison’s disease.

Addison’s disease, if diagnosed, is a manageable condition. But in untreated, it can be fatal.

Related articles:
Symptoms To Watch For In Your Dog: Excessive Drinking (Polydipsia)

Further reading:
Hypercalcemia in Dogs

Categories: Blood workConditionsDiagnosesDog health advocacyExcessive drinkingInterpreting lab resultsReal-life StoriesWorking with Veterinarians

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Jana Rade

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience.

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