Parathyroidectomy — surgical removal of one or more parathyroid glands — costs roughly $2,000 to $4,500 for a dog or cat, and is the standard treatment for primary hyperparathyroidism, a condition where a small, usually benign tumor causes blood calcium to run persistently high.
It is easy to confuse this with thyroid surgery, since the two glands sit next to each other. They are not the same problem, and they are not the same surgery.
Thyroid vs. parathyroid — the mix-up worth clearing up first
The thyroid controls metabolism. The four parathyroid glands, each about the size of a grain of rice and stuck to the surface of the thyroid, control blood calcium. A dog having thyroid surgery is usually being treated for a mass in the neck; a dog having parathyroid surgery is usually being treated for blood work that came back with calcium too high, often before any lump was ever felt.
Primary hyperparathyroidism is the parathyroid version of the story: one of the four glands develops a small, almost always benign adenoma and starts overproducing parathyroid hormone (PTH) without regard for how much calcium the body already has. PTH pulls calcium out of bone and tells the kidneys to hang onto it, so blood calcium climbs and stays climbed.
Why this gets caught, and how
Many dogs with this condition show few obvious signs at first, and the diagnosis starts with a routine blood panel that comes back with an elevated calcium level. When there are symptoms, they're the generic "high calcium" picture: increased thirst and urination, reduced appetite, and lethargy. Because chronically calcium-rich urine is exactly the environment that grows calcium oxalate bladder stones, a first presentation is sometimes a dog straining to urinate — the stone, not the gland, is what brought the pet to the vet.
The diagnostic step that actually confirms the disease is pairing the calcium result with a PTH level. A healthy parathyroid gland should shut off PTH production when calcium is already high — so a PTH reading that is normal, let alone high, sitting next to elevated calcium is itself the abnormal finding. From there, an ultrasound of the neck usually identifies which of the four glands is enlarged.
What the surgery involves
Under general anesthesia, the surgeon exposes the parathyroid glands through a small incision in the neck and removes the enlarged one. In most cases only a single gland is affected, so the other three — suppressed but not diseased — are left in place. The tumor is typically small and the procedure itself is not lengthy by soft-tissue surgery standards; most of the surgical time goes into carefully identifying and preserving the tiny normal glands and the nearby nerves, not the removal itself.
An alternative to surgery exists at some specialty centers: ultrasound-guided heat ablation of the abnormal gland, done without an incision. It's not available everywhere and isn't right for every case — your surgeon or internist will say whether it applies to your pet.
The part that surprises owners: calcium drops after surgery, and that's expected
This is the single most important thing to hear before you go home. For weeks or months, the tumor-affected gland has been telling the other three glands they aren't needed, so those three have gone quiet. Once the diseased gland is removed, it takes those three several days to "wake up" and resume normal PTH production — and in the meantime, calcium can fall, sometimes sharply, over the first two to five days after surgery.
This is why most pets stay hospitalized with calcium checked at least once or twice daily immediately after surgery, and why some go home on oral calcium and vitamin D supplements for a period of weeks while the remaining glands recover. Watch for trembling, muscle twitching, facial rubbing, weakness, or — rarely, if calcium falls very low — seizures, and call your vet promptly if you see them; this is a manageable, monitored part of recovery, not a sign that something went wrong with the surgery itself.
Recovery
- In hospital: typically 1 to 3 days, mainly for calcium monitoring rather than surgical aftercare.
- Incision care: a small neck incision, usually healed within 10 to 14 days; an E-collar prevents scratching at sutures or staples.
- Calcium supplementation: common for the first several weeks after surgery, tapered as blood work confirms the remaining glands have resumed normal function.
- Activity: restricted (no rough play, jumping, or vigorous exercise) until the incision is fully healed.
- Follow-up bloodwork: calcium is rechecked repeatedly in the first weeks, then periodically to confirm the levels have stabilized in the normal range.
Outlook
When the disease is a single benign adenoma — the great majority of cases — removal is curative, and long-term prognosis is very good. Recurrence (a second gland developing disease later) is uncommon but not impossible, which is why most vets recommend periodic calcium rechecks even years after a successful surgery.
Cats get primary hyperparathyroidism far less often than dogs, but it does happen, and the same surgery and the same post-operative calcium-drop pattern apply.
Who isn't a candidate
- Concurrent condition: Severe, unstabilised hypercalcemia with acute kidney injury — bloodwork and IV fluid diuresis to bring calcium down usually come first, since anesthesia in a dehydrated, azotemic patient raises the surgical risk considerably.
- Other: A calcium level and PTH result that don't clearly point to primary hyperparathyroidism — other causes of high calcium (certain cancers, Addison's disease, some fungal infections) need to be ruled out first, because removing a normal gland won't fix a different underlying disease.
- Concurrent condition: Significant heart disease that makes general anesthesia high-risk; ultrasound-guided heat ablation of the abnormal gland is sometimes offered as a non-surgical alternative in that situation, where the expertise is available.
Common questions
What is parathyroidectomy in dogs?
Surgical removal of one or more of the four parathyroid glands, almost always done to treat primary hyperparathyroidism — a benign tumor on one gland that overproduces parathyroid hormone and drives blood calcium persistently high. It's a different gland and a different disease from thyroid surgery, even though the glands sit next to each other.
How much does parathyroid surgery cost for a dog?
Typically $2,000 to $4,500, covering pre-surgical bloodwork and neck ultrasound, the surgery and anesthesia, and the hospitalization needed for calcium monitoring afterward. Costs run higher when hospitalization extends for several days of calcium checks or if a non-surgical ablation alternative is pursued instead.
What causes high calcium in dogs that leads to this surgery?
Most often a small, benign adenoma on one of the four parathyroid glands, which overproduces parathyroid hormone regardless of how much calcium is already in the blood. Other causes of high calcium — certain cancers, Addison's disease, some chronic infections — need to be ruled out first, since they wouldn't be fixed by parathyroid surgery.
Is parathyroid surgery safe for older dogs?
Yes, when the patient is properly stabilized first. Severe, uncorrected high calcium with kidney involvement is usually treated with IV fluids before anesthesia, since a dehydrated, azotemic patient carries more surgical risk. Age alone is not a contraindication; overall health and how well the hypercalcemia has been managed pre-operatively matter more.
What happens to calcium levels after parathyroid gland removal?
Calcium commonly drops, sometimes sharply, over the first 2 to 5 days as the three remaining (previously suppressed) glands take time to resume normal hormone production. This is expected and monitored with hospital bloodwork — usually 1 to 3 days — and many pets go home on oral calcium and vitamin D supplements for several weeks until the remaining glands catch up. Cats get this condition less often than dogs, but the same surgery and the same post-operative pattern apply when they do.
Sources
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