Cow Vaginal Discharge: Normal vs Abnormal, Causes & What to Do

Some vaginal discharge in cows is normal. Around estrus, you may see a small amount of clear, stretchy mucus. After calving, cows also pass lochia, which is part of normal uterine cleanup. In the first 1 to 2 days postpartum, this discharge is often bright red blood mixed with thick mucus and usually has little odor. As the uterus involutes over the following days, the amount should gradually decrease.

Abnormal discharge is more likely when the color, smell, timing, or the cow's attitude changes. Metritis is a uterine infection seen soon after calving and often causes a fetid, watery, reddish-brown discharge along with systemic illness such as fever, depression, poor appetite, and lower milk production. Clinical endometritis tends to show up later, usually after 21 days postpartum, and is more often a purulent or mucopurulent discharge without obvious whole-body illness.

Other causes include retained fetal membranes, which increase the risk of metritis and may be noticed as hanging placenta or a foul discharge if membranes remain inside the uterus. Pyometra can also occur, where pus accumulates in the uterus, sometimes with reduced visible discharge if the cervix is closed. After abortion or breeding problems, infectious reproductive diseases such as trichomoniasis or campylobacteriosis may also be part of the picture, especially in herd situations.

Less common but important causes include trauma to the vagina or cervix after a difficult calving, vaginal prolapse, or contamination from manure in poorly hygienic conditions. Because the same outward sign can reflect very different problems, the cow's calving date, breeding history, appetite, temperature, and milk production all help your vet sort out what is most likely.

A cow can often be monitored closely when the discharge is a small amount of clear mucus during heat, or when she is recently calved and passing expected postpartum lochia that is gradually decreasing, not foul-smelling, and not paired with illness. In these cases, good records matter. Note the calving date, color and odor of the discharge, appetite, milk production, and whether she is bright and eating normally.

You should call your vet promptly if discharge becomes thick, pus-like, foul-smelling, or watery brown-red, or if it continues beyond the expected postpartum window. Purulent or mucopurulent discharge after about 3 weeks postpartum is more concerning for endometritis. A foul discharge with fever or depression in the first days after calving raises concern for metritis.

See your vet immediately if the cow is weak, off feed, feverish, dehydrated, straining, showing abdominal pain, has a retained placenta with systemic illness, or recently had a difficult calving, abortion, or assisted delivery. These signs can point to a more serious uterine infection, trauma, or complications that need same-day care.

If you manage multiple cattle, isolate observation and hygiene practices are important while you wait for guidance. Keep the perineal area and bedding as clean and dry as possible, avoid unnecessary internal exams, and do not give leftover medications without your vet's direction. Delays can reduce fertility and, in severe postpartum infections, can put the cow's life at risk.

Your vet will start with the basics: how long ago the cow calved, whether the birth was difficult, if fetal membranes were retained, whether she has been bred recently, and whether there has been fever, lower milk yield, poor appetite, or repeat breeding. A physical exam often includes temperature, hydration, heart rate, rumen fill, and an external look at the vulva and tail area for the amount and character of discharge.

A reproductive exam may include a vaginal exam, use of a vaginal discharge collection device, vaginoscopy, or rectal palpation to assess the uterus and cervix. In some cases, your vet may recommend ultrasound to look for fluid, pus, retained material, pregnancy, or uterine enlargement. If herd fertility is being affected, they may also discuss testing for reproductive infections such as trichomoniasis or campylobacteriosis.

Treatment depends on the cause and the cow's overall condition. A sick fresh cow with metritis may need systemic therapy, anti-inflammatory support, fluids, and close monitoring. A cow with later purulent discharge but no systemic illness may be managed differently. If retained fetal membranes are present, your vet will usually avoid forceful manual removal because that can worsen damage and infection risk.

Your vet may also talk through herd-level prevention. Clean calving areas, good transition-cow nutrition, prompt attention to dystocia, and careful postpartum monitoring all lower the risk of uterine disease. If fertility is the main concern, follow-up exams may be recommended to confirm the uterus is recovering and to help guide breeding plans.

Home care starts with observation and hygiene, not home treatment. Keep the cow in a clean, dry area with good footing and easy access to water and feed. If she recently calved, monitor her appetite, attitude, milk production, manure, and rectal temperature if your vet has shown you how. Write down when the discharge started, what it looks and smells like, and whether it is improving or worsening.

Clean bedding and a cleaner tailhead and perineal area can help you track discharge more accurately and reduce contamination. Avoid repeated internal checks unless your vet instructs you to do them. Rough or frequent manipulation can irritate tissues and may increase infection risk, especially after a difficult calving.

Do not pull on retained membranes, and do not give leftover antibiotics, hormones, or intrauterine products without veterinary direction. The right plan depends on whether the problem is normal postpartum clearing, metritis, endometritis, pyometra, trauma, or a herd-level reproductive infection. Using the wrong treatment can delay recovery and complicate milk or meat withdrawal decisions.

If your vet recommends monitoring rather than immediate treatment, ask exactly what changes should trigger a recheck. Worsening odor, thicker pus, fever, reduced feed intake, lower milk, straining, or discharge that persists beyond the expected postpartum period all deserve follow-up. Early communication with your vet gives the best chance of protecting both the cow's health and future reproductive performance.