Pig Vaginal Discharge: Normal Heat Sign or a Reproductive Problem?
- A small amount of clear, stringy mucus can happen during estrus (heat), especially with vulvar swelling and standing behavior.
- White, yellow, brown, bloody, or bad-smelling discharge is more concerning for infection, inflammation, trauma, or retained material after farrowing.
- Discharge within about 48 hours after farrowing that is necrotic or foul-smelling is a red flag for metritis and needs prompt veterinary care.
- Mini pigs and pet pigs may hide illness well, so appetite drop, fever, lethargy, or reduced nursing matter as much as the discharge itself.
- Typical US veterinary cost range for an exam and basic workup is about $100-$450; imaging, lab work, hospitalization, or surgery can raise total costs substantially.
Common Causes of Pig Vaginal Discharge
A small amount of clear or slightly cloudy mucus can be a normal sign of estrus in gilts and sows. Merck notes that pigs in heat may show vulvar swelling and vaginal discharge along with behavioral changes such as restlessness, mounting, vocalizing, and standing for pressure over the back. If your pig otherwise seems bright, is eating normally, and the discharge is brief and not foul-smelling, heat is one reasonable possibility.
More concerning causes include metritis after farrowing, vaginitis, urinary contamination around the vulva, trauma from breeding or obstetric manipulation, and less commonly uterine infection such as pyometra. In sows, Merck describes metritis as a white to brown, necrotic, malodorous discharge, often within 48 hours after farrowing, and it may occur with fever, poor appetite, sepsis, mastitis, or low milk production. That combination is not something to watch casually at home.
Feed-related hormone effects can also confuse the picture. Merck reports that the mycotoxin zearalenone can cause estrogen-like effects in pigs, including vulvar enlargement and vulvovaginitis, especially in younger gilts. If several pigs in a group develop swollen vulvas or discharge, your vet may think beyond infection and ask about feed source and storage.
Because discharge can come from the reproductive tract, urinary tract, or skin around the vulva, appearance alone does not always give a full answer. Color, odor, timing around heat or farrowing, and your pig's overall attitude help your vet sort out what is most likely.
When to See the Vet vs. Monitor at Home
See your vet immediately if your pig has discharge plus any of these signs: foul odor, brown or pus-like material, fresh blood, fever, weakness, belly pain, straining, not eating, vomiting, collapse, or recent farrowing. The same is true if piglets are nursing poorly because the sow seems sick or milk production has dropped. Post-farrowing uterine infection can worsen quickly.
You may be able to monitor briefly if the discharge is a small amount of clear mucus and your pig is otherwise acting like she is in heat: swollen vulva, restless behavior, mounting, or standing firmly when pressure is applied over the back. Even then, call your vet if the discharge lasts more than a day or two, becomes cloudy or smelly, or happens outside an expected heat cycle.
For pet pigs, it is smart to have a lower threshold for calling. Many pigs mask pain, and subtle changes like hiding, sleeping more, refusing treats, or becoming less social can be early illness clues. If you are unsure whether the fluid is urine, vaginal discharge, or something from the skin, a photo and short history can help your vet decide how urgently your pig should be seen.
What Your Vet Will Do
Your vet will start with a history and physical exam. Expect questions about your pig's age, whether she is intact or spayed, recent heat signs, breeding exposure, farrowing date, appetite, nursing, fever, and the color, amount, and smell of the discharge. A rectal temperature and careful exam of the vulva, mammary glands, and abdomen are often part of the first visit.
Depending on the case, your vet may recommend cytology or culture of the discharge, urinalysis, blood work, and imaging such as ultrasound. Ultrasound is often useful when your vet needs to look for retained fetal material, uterine fluid, pregnancy, or a swollen infected uterus. If your pig is painful, stressed, or hard to handle safely, sedation may be needed.
Treatment depends on the cause. Options may include monitoring a normal heat cycle, systemic antibiotics when infection is suspected, anti-inflammatory medication, fluids, supportive care for a sick postpartum sow, and treatment of any related mastitis or low milk production. In severe or recurrent reproductive disease, your vet may discuss surgery, including spay, if that fits your pig's health status and future plans.
Treatment Options
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Office or farm-call exam
- Temperature check and reproductive history review
- Focused physical exam of vulva, abdomen, and mammary glands
- Short-term monitoring plan if discharge appears consistent with normal heat
- Basic medications if your vet feels infection or inflammation is likely
Recommended Standard Treatment
- Exam plus basic diagnostics such as cytology, urinalysis, or blood work
- Reproductive ultrasound when indicated
- Systemic antibiotics if your vet suspects metritis or another infection
- Pain control or anti-inflammatory medication when appropriate
- Recheck visit to confirm the discharge is resolving
Advanced / Critical Care
- Emergency evaluation and hospitalization
- IV fluids and intensive supportive care
- Expanded blood work and repeat imaging
- Treatment for severe metritis, sepsis, mastitis, or poor milk production
- Sedation, procedures, or surgery such as ovariohysterectomy in selected cases
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Pig Vaginal Discharge
Bring these questions to your vet appointment to get the most out of your visit.
- Does this discharge look more like normal heat mucus or a reproductive infection?
- Based on her age and history, what are the most likely causes in my pig?
- Does she need an ultrasound, cytology, culture, urinalysis, or blood work today?
- Are there signs of metritis, retained material after farrowing, vaginitis, or urinary tract disease?
- What changes at home would mean I should bring her back right away?
- If she is postpartum, how should I monitor nursing, milk production, appetite, and temperature?
- What treatment options fit a conservative, standard, or advanced plan for this case?
- Would spaying help prevent future reproductive problems in my pig?
Home Care & Comfort Measures
Keep your pig in a clean, dry, low-stress area while you monitor her. Gently note the discharge color, amount, and odor once or twice daily, and track appetite, water intake, manure, urination, and energy level. If she recently farrowed, also watch whether piglets are nursing well and whether the mammary glands look swollen, hot, or painful.
Do not put creams, antiseptics, or home flushes into or around the vulva unless your vet tells you to. Those products can irritate tissue, hide important clues, or make infection harder to assess. If the skin around the vulva is soiled, you can clean the outside gently with warm water and pat dry.
If your vet has advised monitoring for possible heat, reduce handling stress and keep good notes on behavior such as restlessness, mounting, vocalizing, and standing response. If the discharge becomes cloudy, bloody, brown, or foul-smelling, or your pig stops eating, becomes lethargic, strains, or seems painful, move from home monitoring to a veterinary visit right away.