Veterinary Guide to Canine Hyperparathyroidism 2025 🩺🐶

By Dr. Duncan Houston BVSc

🧬 What Is Hyperparathyroidism?

Hyperparathyroidism is a condition marked by excessive production of parathyroid hormone (PTH), leading to abnormally high blood calcium (hypercalcemia). In dogs, this can be due to:

• Primary: a tumor (adenoma, carcinoma) or hyperplasia producing PTH autonomously.
• Secondary: caused by chronic kidney disease or dietary imbalances, prompting compensatory overproduction of PTH.

👥 Who’s Affected?

• Primary: typically older dogs (5–15 years); common breeds include Keeshonds (genetic risk), Labs, GS‑dogs, Goldens, Poodles, Shih Tzus, Cocker Spaniels.
• Secondary: any dog with chronic kidney disease or severe calcium/Vitamin D imbalance.

👀 Signs to Watch

Clinical signs often reflect elevated calcium ("stones, bones, groans, thrones, and psychiatric overtones"):

• Increased thirst & urination; urinary stones or UTIs common (~30–50 %).
• Lethargy, muscle weakness, twitching, trembling.
• GI upset—vomiting, reduced appetite, constipation.
• In severe cases: stupor, coma, bone fracturing (“rubber jaw”).

🔬 Diagnosis Pathway

1. Bloodwork: Elevated total & ionized calcium, low phosphorus; elevated PTH alongside normal/low PTHrP confirms primary disease.
2. Urinalysis: Check for stones, UTIs, and dilute urine.
3. Imaging:
   • Cervical ultrasound for enlarged parathyroids (>4 mm suggestive of adenoma.
   • Abdominal imaging to screen for stones, kidney disease.
   • Thoracic X-rays to rule out cancer-linked hypercalcemia.
   • CT is available for precise surgical planning.
4. Differential diagnoses: exclude cancer, Addison’s, vitamin D toxicity, granulomatous disease.

📈 Primary vs Secondary Comparison

🛠️ Treatment Approaches

🔹 Primary Hyperparathyroidism

• Parathyroidectomy: surgical removal of affected gland(s)—gold standard with ~90% cure rate.
• Minimally invasive ablation: ultrasound-guided ethanol or heat ablation—high success (~90%), less invasive.
• Peri-op care: hospital fluids, close ionized calcium monitoring, and supplements as needed due to post-op hypocalcemia risk.

🔹 Secondary Hyperparathyroidism

• Correct calcium/Vitamin D ratio—balanced diet, supplementation.
• Manage underlying CKD—dietary phosphorus restriction, renal therapies.
• Supplemental calcium or calcitriol may be required short‑term.

⌛ Prognosis & Monitoring

• Primary: Prognosis excellent with surgery or ablation; monitor calcium for 1–2 weeks post-op.
• Secondary: Prognosis varies—good if caught early, guarded if CKD-associated.
• Schedule follow-ups: calcium, phosphorus, renal values, imaging, and blood pressure every 1–3 months initially.

🏡 Home Care & Lifestyle

• Stick to prescribed diets and supplements carefully.
• Provide fresh water and encourage drinking.
• Watch for signs of urine changes, stones, or lethargy.

📱 Ask A Vet Ecosystem Support

• Tele‑app consults: Upload lab/imaging to adjust medications and diet remotely.
• Reminders: Manage calcium checks, medications, supplements via app..

🎓 Case Spotlight: “Zoey” the Keeshond

Zoey, 11 years old, was diagnosed after routine bloodwork showed Ca 12.5 mg/dL. Ultrasound revealed a 7 mm parathyroid adenoma. She had surgical removal and was monitored—calcium normalized, and she’s now thriving with regular remote Check‑Ins via Ask A Vet! 🐕💖

🔚 Key Take-Home Messages

1. Excess PTH leads to hypercalcemia with non‑specific signs—always check calcium & PTH.
2. Primary disease—surgery or ablation are effective; monitor calcium closely post-op.
3. Secondary causes include CKD and dietary imbalance—manage underlying disease accordingly.
4. Home care and consistent vet follow-up support long-term wellbeing.
5. Ask A Vet helps every step—from diagnosis to diet and monitoring—virtually every time. 🩺📲

Dr Duncan Houston BVSc, founder of Ask A Vet. Download the Ask A Vet app for remote endocrine monitoring, calcium tracking, and guidance for your pup’s parathyroid health! 🐶❤️