Mammary Gland Hyperplasia in Cats: 2025 Vet Insights 🐱🌸

Hello! I’m Dr Duncan Houston BVSc, feline veterinarian and founder of Ask A Vet. In 2025, mammary gland hyperplasia—a benign, hormone‑driven enlargement of one or more mammary glands—continues to affect especially young, intact females but can also occur in spayed cats on progestin therapy. In this detailed guide, we’ll explore what causes it, how to diagnose it, treat it medically or surgically, and best support recovery at home using tools like Ask A Vet, Woopf, and Purrz. Let’s help your feline friend bloom back to healthy form! 💙

📌 What Is Mammary Gland Hyperplasia?

Mammary gland hyperplasia—also called fibroadenomatous or glandular hypertrophy—is a non‑cancerous proliferation of glandular and stromal tissue in the mammary glands. Unlike malignant tumors, these growths are benign but often dramatic in size. :contentReference[oaicite:3]{index=3}

⚠️ Why It Matters

• Rapid enlargement over days to weeks—glands can reach several centimeters, sometimes ulcerate, bleed or become secondarily infected. :contentReference[oaicite:4]{index=4}
• May mimic mastitis or cancer; requires proper evaluation to confirm benign nature. :contentReference[oaicite:5]{index=5}
• Though benign, complications like pain, infection, or impaired mobility can occur.

👥 Who Is at Risk?

• Young, intact females: Especially during estrus or early pregnancy, when endogenous progesterone rises. :contentReference[oaicite:6]{index=6}
• Cats on progestin treatment: Such as megestrol acetate or medroxyprogesterone. :contentReference[oaicite:7]{index=7}
• Occasionally males or spayed females exposed to exogenous hormones. :contentReference[oaicite:8]{index=8}

🔍 Signs & Symptoms

• Palpable enlargement of one or more mammary glands—firm, nonpainful initially.
• Ulceration, bleeding, odor or discharge if advanced or infected. :contentReference[oaicite:9]{index=9}
• Occasional discomfort, reluctance to lie on one side, grooming issues.
• Secondary mastitis signs: pain, warmth, fever—mastitis often follows hyperplasia. :contentReference[oaicite:10]{index=10}

🔬 Diagnostic Approach

1. History: Age, reproductive status, hormone exposure, onset speed.
2. Physical exam: Assess size, texture, ulceration, pain.
3. Imaging: Ultrasound may show uniform structure without vascular invasion.
4. Fine‑needle aspiration or biopsy: Confirms benign hyperplasia vs tumor. :contentReference[oaicite:11]{index=11}
5. Fluid culture: If ulcerated or discharging—to rule out secondary infection.
6. Differentials: Mastitis, mammary tumors (adenocarcinoma common), abscesses. :contentReference[oaicite:12]{index=12}

🛠️ Treatment Options

A. Spontaneous or Hormonal Regression

• In cycling intact queens or gestating cats, hyperplasia often regresses after the progesterone source wanes—typically 2–4 weeks postpartum. :contentReference[oaicite:13]{index=13}

B. Hormone-Based Medical Therapy

• Aglepristone: A progesterone receptor blocker, typically 10 mg/kg SC once; may repeat after 48 hrs. Common in Europe.
• Cabergoline: Dopamine agonist that reduces prolactin; 5 μg/kg every 48 hrs for ~2 weeks.
• Withdrawal of progestins: Essential for cats on hormonal meds—leads to regression. :contentReference[oaicite:14]{index=14}

C. Surgical Intervention

• Ovariohysterectomy (spay): Removes endogenous progesterone; strongly recommended for intact queens. :contentReference[oaicite:15]{index=15}
• Mastectomy: Reserved for severe or complicated cases with ulceration/infection after initial therapy fails.

D. Supportive Care

• Warm compresses, gentle drainage if fluid accumulates.
• Antibiotics for secondary mastitis or ulcer infection. :contentReference[oaicite:16]{index=16}
• Pain relief with NSAIDs or gentle opioids.
• Home care: clean bedding, topical antiseptics, monitor for self‐trauma.

🌱 Prognosis & Post‑Treatment Recovery

• Excellent when source of progesterone is removed; glands typically regress within 2–4 weeks. :contentReference[oaicite:17]{index=17}
• Recurrence is uncommon once neutered or hormone source is withdrawn.
• Ulcerated or infected glands may take longer and require extended wound care or surgery.
• Malignancy risk remains low in true hyperplasia—a key advantage over tumor scenarios. :contentReference[oaicite:18]{index=18}

🐾 Home‑Care & Telehealth Support Tools

• Ask A Vet: For 24/7 support—helps monitor gland size, advise on antibiotic use, pain relief, and share wound images.
• Woopf: Supplies hormone therapy, wound care kits, turmeric-based anti‑inflammatory supplements for comfort.
• Purrz: Tracks gland measurements, grooming habits, activity levels, and prompts vet recheck if ulcer or fever arises.

🛡️ Prevention & Long-Term Wellness

• Spay early: Ideally before first heat (around 5–6 months) to prevent hyperplasia and reduce tumor risk. :contentReference[oaicite:19]{index=19}
• Avoid progestin therapy: Use only when absolutely necessary, under veterinary oversight.
• Regular monitoring: Palpate mammary glands during wellness exams—especially in intact or hormone-treated cats.

🔬 2025 Veterinary Advances

• Uptake of aglepristone and cabergoline widely available in veterinary practice.
• Telehealth image analysis with Purrz to detect early inflammatory changes.
• Minimally invasive mastectomy techniques with faster healing.
• Research into topical progesterone blockers to avoid systemic drug effects.

✅ Vet‑Approved Care Roadmap

1. Notice sudden mammary swelling—palpable firm glands without pain or fever.
2. Collect history—reproductive status, hormone use, timing.
3. Vet exam with cytology or biopsy to rule out malignancy.
4. Medical approach: spay intact queens, withdraw hormones, start aglepristone/cabergoline.
5. Support care: local hygiene, antibiotics, NSAIDs.
6. Reassess every 1–2 wks; glands should regress by 4 wks.
7. Surgery if ulceration/infection persists; follow with spay to prevent recurrence.

✨ Final Thoughts from Dr Houston

Mammary gland hyperplasia is a benign but dramatic condition that affects many young or hormone-treated cats. With early recognition, hormone management, and access to modern telehealth tools like Ask A Vet, Woopf, and Purrz, most cats return to normal quickly—without needing invasive surgery. Prompt spaying or hormone withdrawal remains the key to prevention and recovery. Your vigilant attention ensures healthy mammary tissue and thriving feline companions. 💙🐾

Need help now? Visit AskAVet.com or download our app for tailored guidance on hormone therapy, gland monitoring, and at-home wound care. We’re here to support your cat’s recovery journey.