Hydrometra, Mucometra, and Pyometra in Dogs and Cats: A 2025 Guide to Uterine Disease 🐶🐱🩺

Hello, I’m Dr Duncan Houston BVSc. Uterine disease in intact female dogs and cats can range from a silent buildup of fluid to life-threatening infection. Understanding hydrometra, mucometra, and pyometra helps you take proactive steps before these conditions become critical. This 2025 guide walks you through how they develop, the signs to watch for, and the treatments available. 🧬

🧪 What Are These Conditions?

• Hydrometra: Sterile, watery fluid in the uterus
• Mucometra: Sterile mucus fluid buildup
• Pyometra: Pus-filled uterus caused by bacterial infection—a medical emergency

All three are linked to the hormone progesterone, which rises after heat and causes the uterus to thicken and suppress its immune defenses. If pregnancy doesn’t occur after multiple cycles, cysts form, fluid builds, and infection may follow. 📉

💥 How Pyometra Develops

• 🧫 Bacteria enter the uterus through the cervix
• 🔥 Uterus is vulnerable after heat due to hormonal changes
• 🦠 Pus builds up; pressure rises; uterus can rupture
• ☠️ Rupture leads to deadly peritonitis and sepsis

Hydrometra and mucometra don’t involve infection, but they increase the risk of developing pyometra later. 🚨

📸 Diagnosis

• 🖥️ Ultrasound: Confirms fluid buildup, helps rule out pregnancy
• 📸 X-rays: Can show uterine enlargement
• 🧪 Blood work: Looks for infection, anemia, and organ damage

⚠️ Symptoms to Watch For

Hydrometra/Mucometra

• 😐 Often no symptoms
• 🛑 May cause infertility if left untreated

Pyometra

• 🩸 Vaginal discharge
• 😵 Lethargy, vomiting, poor appetite
• 📈 Increased thirst and urination
• 🤢 Bloated belly
• 🩺 Fever, shock, collapse

Pyometra is a life-threatening emergency. Immediate veterinary care is essential. 🏥

💊 Treatment Options

Hydrometra & Mucometra

• 💉 Dinoprost (Lutalyse): Induces uterine contractions to expel fluid
• 🧼 Vaginal saline infusion
• 🔁 Risk of recurrence is high
• 🩺 Spaying is the only permanent solution

Pyometra

• 🔪 Emergency spay surgery (ovariohysterectomy) is required
• 💉 Antibiotics
• 💧 IV fluids and hospitalization

Some attempts are made to medically manage pyometra in breeding animals, but it’s rarely successful. Spaying is the safest and most effective cure. 🧠

🛡️ Prevention

• 🗓️ Spaying before the first or second heat cycle prevents all three conditions
• 🐾 Older intact females are at highest risk
• 🧪 Monitor any abnormal discharge, behavior, or belly swelling

Pyometra typically occurs in females 6–8 weeks post-heat. That’s the critical window to watch. ⏱️

📱 Ask A Vet: Support for Uterine Health

• 💊 Help navigating dinoprost vs. surgery
• 📋 Spay timing & post-op care guidance
• 🩺 Emergency triage signs to act on

Access expert advice anytime at AskAVet.com or through the Ask A Vet app. 🐶📲

✅ Summary: Uterine Disease in Pets

• 🧪 Hydrometra = watery fluid; Mucometra = mucus; Pyometra = pus & infection
• 🔁 Hydrometra/mucometra may be silent but lead to pyometra
• 🩸 Pyometra is deadly and needs emergency surgery
• 🧼 Spaying prevents all uterine fluid diseases
• 🧪 Diagnosis by ultrasound, labs, and signs

Hydrometra, mucometra, and pyometra are all avoidable with spaying. If your pet is intact and showing signs, act fast—early intervention saves lives. 🐕❤️

— Dr Duncan Houston BVSc