Pig Swollen Vulva: Heat Cycle, Irritation or Infection?

A swollen vulva in a female pig is not always an emergency. In intact gilts and sows, vulvar swelling can be part of a normal heat cycle. Merck notes that pigs are polyestrous year-round, with a cycle averaging about 21 days, and vulvar swelling or discharge may develop 2 to 3 days before estrus. These physical signs are often more noticeable in gilts than in mature sows.

Other causes are more medical than hormonal. Skin irritation from urine scald, damp bedding, rough surfaces, or rubbing can make the vulva look puffy and red. Mounting by pen mates can also cause bruising or soft-tissue swelling. If the area looks raw, crusted, or painful, irritation or trauma moves higher on the list.

Infection is another possibility. Vaginitis, urinary tract infection, and reproductive tract disease can all cause swelling, discharge, odor, or discomfort. In miniature pet pigs, Merck notes that cystitis is common and may cause frequent urination or straining. In recently farrowed pigs, a foul-smelling vaginal discharge can point to metritis, a uterine infection that needs prompt veterinary care.

Less common causes include congenital anatomy issues, masses, cysts, or retained reproductive tissue after surgery. Because the same outward sign can come from heat, skin disease, urinary disease, or reproductive disease, your vet usually needs to examine the pig and match the swelling with age, spay status, breeding history, discharge, and behavior.

You may be able to monitor at home for 24 to 48 hours if your pig is bright, eating normally, urinating normally, and the vulva is only mildly enlarged without odor, discharge, or pain. This is especially true in an intact young female that may be cycling. Keep notes on appetite, urination, behavior, and whether the swelling seems to come and go on a roughly 3-week pattern.

Schedule a routine vet visit soon if the swelling lasts beyond a couple of days, keeps returning without a clear heat pattern, or is paired with licking, rubbing, redness, or mild discharge. A non-emergency appointment is also wise if your pig is not spayed and you are unsure whether she is cycling, or if she has had recent breeding, farrowing, or surgery.

See your vet immediately if there is foul-smelling discharge, pus, significant bleeding, fever, lethargy, reduced appetite, belly pain, repeated straining to urinate, or signs that urination is blocked. Those signs can fit urinary disease, severe vaginitis, trauma, or uterine infection. A pig that is weak, collapsed, breathing hard, or unable to pass urine needs urgent care the same day.

If your pig recently gave birth, treat vulvar swelling plus discharge, fever, or poor appetite as more urgent. Merck describes metritis in sows as being diagnosed by the appearance and bad odor of the vaginal discharge, and postpartum illness can worsen quickly.

Your vet will start with the basics: age, whether your pig is spayed, timing of the swelling, any discharge, urination changes, breeding exposure, and whether she recently farrowed. They will check temperature, hydration, body condition, and the skin around the vulva and tail. In some pigs, a gentle exam is enough to separate likely heat from obvious irritation or trauma.

If infection or urinary disease is possible, your vet may recommend urinalysis and urine culture. Merck notes that in miniature pet pigs, urinalysis, bacteriologic culture, bloodwork, radiography, and ultrasonography are important tools when cystitis or urinary disease is suspected. These tests help your vet tell apart bladder infection, stones, kidney involvement, and reproductive causes of discharge.

For pigs with discharge, pain, or a history that suggests reproductive disease, your vet may suggest cytology, culture, ultrasound, or other imaging. Ultrasound can help look for uterine enlargement, fluid, pregnancy-related problems, masses, or retained tissue. Sedation may be needed for a safe and thorough exam in some pet pigs.

Treatment depends on the cause. Your vet may recommend skin care and environmental changes for irritation, targeted medication for infection, pain control, or more advanced care if there is urinary obstruction, severe reproductive disease, or a surgical problem. If your pig is intact and not intended for breeding, your vet may also discuss whether spaying could reduce future reproductive issues.

Keep the area clean and dry. Replace damp or soiled bedding promptly, and use soft, low-dust bedding that does not rub the vulva. If urine scald is possible, gently clean the skin with lukewarm water and pat dry. Do not use scented wipes, peroxide, essential oils, diaper creams, or over-the-counter human vaginal products unless your vet tells you to.

Watch your pig closely for appetite, water intake, urination, stool output, energy level, and any discharge or odor. Taking a daily photo can help you track whether the swelling is improving, stable, or getting worse. If your pig is intact, note whether the swelling seems to repeat every 18 to 24 days, which can support a heat-cycle pattern.

Reduce friction and trauma. Separate from rough pen mates or mounting animals if the area looks bruised or sore. Make sure flooring is not abrasive and that your pig can rest on a clean, dry surface. Encourage normal hydration unless your vet has given different instructions.

Home care is supportive, not a substitute for diagnosis. If swelling becomes painful, discharge appears, urination changes, or your pig seems unwell, contact your vet promptly. See your vet immediately if your pig cannot pass urine, has a foul-smelling discharge, or seems weak or distressed.