Hyperparathyroidism in Dogs
What is Hyperparathyroidism in Dogs?
Hyperparathyroidism is a treatable condition that causes calcium levels in the blood to become too high. It usually happens when one small gland in the neck makes too much parathyroid hormone, also called PTH.
The growth causing the problem is usually benign, meaning it does not spread like cancer. However, high calcium can still damage the kidneys and other organs if it is not treated. Many dogs are first diagnosed when routine bloodwork shows unexpectedly high calcium.
Why is High Calcium Dangerous for Dogs?
Calcium helps your dog’s muscles, nerves, and organs work normally. However, too much calcium in the blood can damage the kidneys and make your dog feel sick.
High calcium may cause:
- Kidney injury or kidney failure
- Increased thirst and urination
- Dehydration
- Weakness or low energy
- Vomiting or decreased appetite
- Heart rhythm changes in severe cases
Because high calcium can quietly damage the kidneys, persistent elevations should always be investigated.
What Causes Hyperparathyroidism in Dogs?
In most dogs, primary hyperparathyroidism is caused by a small tumor affecting one of the parathyroid glands. These glands are located near the thyroid gland in the neck.
These tumors are usually benign adenomas, which means they do not spread to other parts of the body. However, they still produce too much hormone, causing calcium levels to stay overly elevated.
Why a Benign Tumor Can Still Cause Problems
Parathyroid hormone controls how calcium moves throughout the body. When too much hormone is produced, it causes:
Release of calcium from bones
Reduced calcium removal by the kidneys
Increased calcium absorption from the intestines
Over time, this constant imbalance places stress on the kidneys and other organs – which is why treatment focuses on correcting the hormone source.
What Signs of Hyperparathyroidism Can You See at Home?
Some dogs show very subtle signs, while others may experience:
- Increased drinking and urination
- Decreased appetite
- Vomiting
- Weakness or low energy
- Weight loss
Because symptoms can be mild early on, many dogs feel relatively normal despite dangerous calcium levels.
How is Hyperparathyroidism Diagnosed in Dogs?
Diagnosing hyperparathyroidism starts with confirming that your dog’s calcium is truly high. From there, your veterinarian may recommend tests to find out why. Testing may include:
- Bloodwork to confirm high calcium
- Parathyroid hormone (PTH) testing
- Kidney function testing
- Ultrasound imaging to identify the affected gland
Since many conditions can cause hypercalcemia, evaluation by an internal medicine specialist is often recommended.
How is Hyperparathyroidism Treated in Dogs?
Hyperparathyroidism is highly treatable once identified. The goal of treatment is to stop the abnormal gland from producing too much hormone so calcium levels can return to normal.
Surgical Removal
Surgery removes the abnormal gland and can be curative, but typically requires hospitalization and close monitoring afterwards.
Minimally Invasive Ethanol Ablation
Many dogs are candidates for ultrasound-guided ethanol ablation. This minimally invasive procedure destroys the abnormal tissue without surgery and may allow for a faster, smoother recovery.
What is the Outlook for Dogs with Hyperparathyroidism?
With appropriate treatment, calcium levels often return to normal. Lowering calcium helps protect the kidneys and and allows most dogs to feel better and return to normal activity.
Hyperparathyroidism is unique because:
- The tumor is usually benign
- The illness is caused by hormone imbalance, not cancer
- High calcium can become an emergency if untreated
- Early diagnosis often leads to excellent outcomes
If your dog has elevated calcium levels, further evaluation helps identify the cause and prevent long-term complications.
Hyperparathyroidism can sound intimidating, but many dogs to very well once the cause of high calcium is identified and treated. If your dog has elevated calcium levels or ongoing symptoms, our internal medicine team can help determine the next step and recommend a treatment plan tailored to your dog’s needs.
When Should You Seek Evaluation?
If your dog has been diagnosed with high calcium, further evaluation is recommended. You should also contact your veterinarian if your dog is drinking more, urinating more often, vomiting, eating less, or acting unusually tired.
Even mild symptoms can matter. Persistently high calcium can affect kidney health over time, and early testing can help prevent complications.
Frequently Asked {Questions}
What is hyperparathyroidism in dogs?
Hyperparathyroidism occurs when one of the small parathyroid glands in the neck produces too much hormone, causing calcium levels in the blood to rise. Although the underlying growth is usually benign, elevated calcium can affect important organs over time if left untreated.
Is hyperparathyroidism cancer?
In most dogs, no. The condition is typically caused by a benign (non-cancerous) tumor called an adenoma. While it rarely spreads, it can still cause illness because it disrupts the body’s calcium balance, which is why treatment is important.
How serious is high calcium in dogs?
High calcium levels can place stress on the kidneys and other organs, even when a dog seems to feel normal. Over time, untreated hypercalcemia can lead to kidney damage, dehydration, and weakness. Early diagnosis helps prevent long-term complications.
What signs of hyperparathyroidism might I notice at home?
Some dogs show increased thirst and urination, decreased appetite, vomiting, or low energy. However, many dogs have very subtle signs, and the condition is often discovered during routine bloodwork before obvious symptoms appear.
How is hyperparathyroidism diagnosed in dogs?
Diagnosis involves confirming elevated calcium levels and measuring parathyroid hormone (PTH), along with imaging such as ultrasound to identify the affected gland. Because several conditions can cause high calcium, careful testing helps ensure the correct diagnosis.
Is hyperparathyroidism treatable?
Yes! Hyperparathyroidism is highly treatable, and many dogs are cured once the abnormal gland is addressed. Treatment options may include surgery or minimally invasive procedures designed to stop excess hormone production.
Will my dog feel better after treatment?
Most dogs improve significantly once calcium levels return to normal. Increased energy, improved appetite, and better hydration are commonly seen as the body regains balance.
What is the long-term outlook for dogs with hyperparathyroidism?
The prognosis is excellent when the condition is diagnosed and treated appropriately. Many dogs return to normal lives after treatment, especially when kidney health is preserved through early intervention.
