Canine Ovarian Tumors – Vet Guide 2025 🐶🔬🩺

By Dr. Duncan Houston BVSc

Hi there! I’m Dr Duncan Houston, BVSc, founder of Ask A Vet. Though uncommon, ovarian tumors in female dogs can be serious—often malignant and hormonally active. Early detection, accurate staging, and prompt surgical treatment offer the best chance for recovery. This detailed 2025 guide explores tumor types, clinical signs, diagnostic work-ups, surgical and adjunctive therapies, prognosis, and how you can support your dog before and after treatment.

📘 What Are Ovarian Tumors?

Ovarian tumors arise in intact female dogs and include three main cell types:

• Epithelial tumors (40–50%)—papillary adenomas/carcinomas; the most common type.
• Germ cell tumors (6–20%)—dysgerminomas, teratomas.
• Sex cord–stromal tumors (34–50%)—granulosa cell, Sertoli‑Leydig tumors; often hormone-secreting.

🔬 Epidemiology & Risk Factors

• Rare: make up ~0.5–1.2% of canine tumors.
• Most common in older, intact, nulliparous females.
• Breed predispositions include German Shepherds, Boston Terriers, Poodles, and Pointers.
• Spaying early prevents the risk of ovarian (and uterine) tumors; intact status significantly elevates risk.

🚩 Clinical Signs to Watch For

• Estrus abnormalities: prolonged or abnormal “heat” cycles.
• Vulvar swelling or discharge (may be hemorrhagic).
• Abdominal distension, pain, or ascites.
• Behavioral changes from hormone production—aggression, mammary enlargement or alopecia.
• Non-specific signs: lethargy, anorexia, fever, respiratory distress if spread to the lungs or chest cavity.

🔍 Diagnostic Work‑up

1. Physical exam & palpation—may detect enlarged ovarian mass or fluid.
2. Bloodwork & urinalysis—usually unremarkable but helpful for baseline and staging.
3. Imaging:
   • Abdominal ultrasound—best for detecting ovarian masses, cysts, and ascites.
   • Radiographs—evaluate lungs and chest for metastasis.
   • CT/MRI—for detailed staging if metastasis is suspected.
4. Fine-needle aspirate or surgical biopsy—definitive diagnosis and classification.
5. Full staging: includes chest imaging, abdominal ultrasound, and sampling of lymph nodes or fluids before surgery.

🔧 Treatment Protocols

Surgical Management

• Ovariohysterectomy (OHE): removal of ovaries and uterus is primary treatment; often curative for early-stage tumors.
• Unilateral oophorectomy: may be used in select benign cases, though full OHE is preferred.
• Extended surgery: removal of involved tissues, lymph nodes, or metastases if identified.

Adjunctive Therapies

• Chemotherapy: considered when metastasis is present; cisplatin intracavitary therapy has also shown benefit for effusive tumors.
• Palliative care: pain management, fluid drainage, and supportive nutrition for advanced cases where surgery isn't feasible.

Post‑Op Care & Monitoring

• Pain control with NSAIDs and opioids as needed.
• Manage hormone-driven changes—supportive feeding, treat alopecia.
• Recheck labs and imaging every 3–6 months to monitor for recurrence or metastasis.

📈 Prognosis & Outcomes

• Localized tumors that undergo complete removal generally have a good to excellent prognosis.
• Metastatic disease carries a guarded to poor outlook; chemotherapy may improve quality and duration, but cure is rare.
• Long-term outcomes vary—range depends on tumor type, staging, and treatment success.

🏠 Home Care Tips

• Convalescence post-spay: crate rest, gradual return to normal activity.
• Monitor incision for swelling, discharge, or dehiscence.
• Maintain nutritious, easily digestible diet during recovery.
• Keep follow-up schedules with the vet for scans and exams.
• Provide emotional support—soft bedding, gentle attention, consistent routines.

✨ Key Takeaways

• Ovarian tumors, though rare, are often malignant and hormonally active in intact female dogs.
• Signs include estrus irregularities, vulvar discharge/swelling, abdominal enlargement, and behavior changes.
• Diagnosis requires imaging, biopsy, and staging before surgery.
• Surgical removal via spay is primary treatment; chemo for metastatic disease.
• Early detection and intervention maximize prognosis and long-term recovery.
• Home support and vigilant follow-up enhance outcomes and wellbeing.

🐾 Ask A Vet

• Get oncology or surgical advice through Ask A Vet.

If you notice abnormal heat cycles, vulvar discharge, or abdominal swelling in an intact female—especially older—don’t delay. Schedule diagnostics and consider spaying promptly. Early treatment offers the best hope. Reach out to your vet or Ask A Vet now. 🩺