A cow’s placenta normally passes within 3 to 8 hours after delivering a calf. If the membranes haven’t been expelled within 24 hours, the placenta is clinically considered retained, and you need a plan. The approach has shifted significantly in recent years: aggressive manual removal is no longer the standard recommendation, and patience combined with monitoring is often the better path.
Why the Placenta Gets Stuck
The placenta attaches to the uterine wall through small button-like connections called cotyledons. After calving, reduced blood flow and immune cell activity at these attachment points cause them to break down naturally, releasing the membranes. When that process fails, the placenta stays attached.
Several factors increase the risk. Difficult or assisted calvings are a major one. Twins, premature births, and cesarean sections all raise the likelihood. Nutritional deficiencies play a significant role too. In one study, increasing selenium intake for at least three weeks before calving (from 0.23 mg to 0.92 mg daily) reduced retained placenta incidence from 38% to zero. Low calcium levels after calving, even when the cow doesn’t show obvious signs of milk fever, compromise both immune function and muscle contraction, making it harder for the uterus to push the membranes out. Cows with subclinical low calcium are nearly five times more likely to develop uterine infections afterward.
The Case Against Manual Removal
For decades, the instinct was to reach in and peel the placenta off the uterine wall by hand. This is no longer considered best practice in most situations. The placental attachments are tightly fused to uterine tissue, and pulling the membranes free tears the uterine lining, creating wounds that bacteria colonize rapidly. The damage from forced removal often causes worse problems than leaving the placenta alone.
If membranes are hanging from the vulva, you can trim them to about hock level to reduce the risk of the cow stepping on them or catching them on equipment. Tying the hanging membranes in a loose knot serves the same purpose. But pulling or applying steady traction to drag the placenta out is a different matter entirely and risks serious uterine injury.
When Gentle Traction Works
There is a narrow window where light manual assistance makes sense. If the placenta has partially detached and is loosely hanging, gentle traction (not forceful pulling) can help membranes that are already separating on their own. The key distinction: if you feel resistance at the attachment points, stop. A placenta that peels away easily with minimal pressure was nearly ready to come out anyway. One that requires real force is not ready, and forcing it causes harm.
This kind of assessment is best done by a veterinarian or someone with hands-on experience, using proper hygiene. Clean gloves, a clean perineal area, and careful technique matter. Introducing bacteria into an already compromised uterus turns a manageable situation into a dangerous infection.
Hormonal Treatments to Speed Expulsion
Oxytocin, the same hormone that drives uterine contractions during calving, can encourage placental expulsion when given at the right time. Research shows that an intramuscular injection of 50 IU of oxytocin given between 3 and 6 hours after calving accelerates membrane passage, particularly in cows that needed calving assistance. The timing matters: oxytocin works best while the uterus is still naturally responsive to it. After 24 to 48 hours, the window of effectiveness narrows considerably.
Prostaglandin injections are sometimes used as well, though their primary role is stimulating uterine contractions and promoting involution (the uterus shrinking back to normal size) rather than directly detaching the placenta. Your veterinarian can determine which hormonal approach fits your cow’s situation based on how much time has passed and the cow’s overall condition.
Managing a Cow With Retained Membranes
If the placenta hasn’t passed by 24 hours, the most important thing you can do is monitor the cow closely rather than intervene aggressively. Many cows will shed the membranes on their own within a few days as the tissue naturally breaks down. During this time, watch for two warning signs: a rectal temperature above 102.5°F, and loss of appetite. Either of these suggests the cow is developing a uterine infection and needs treatment.
Take the cow’s temperature twice daily for the first week after calving. A cow with retained membranes that maintains a normal temperature and keeps eating is handling the situation. A cow that spikes a fever and goes off feed is not. The membranes will become discolored, smell bad, and gradually decompose. This looks alarming but is part of the natural breakdown process. The smell alone is not a reason to panic, though it is unpleasant.
Treating Secondary Infections
When a retained placenta leads to uterine infection (metritis), antibiotic treatment becomes necessary. This is the complication that actually causes long-term damage. Research shows that retained placenta alone does not significantly impair a cow’s future reproductive performance. Metritis does. Cows that develop metritis, whether or not a retained placenta triggered it, take significantly longer to cycle, require more services per conception, and have extended calving intervals.
Antibiotics can be delivered systemically (by injection) or directly into the uterus. Intrauterine treatments with oxytetracycline have been a traditional approach, and newer protocols using combinations of antiseptic compounds and antibiotics infused into the uterus have shown promise. Systemic antibiotics treat the cow’s whole body and are typically preferred when she’s showing signs of illness like fever and depression. The choice between systemic and local treatment depends on severity, and this is a decision for your veterinarian.
Preventing Retained Placenta in Your Herd
Prevention is far more effective than treatment, and most of it comes down to nutrition and calving management.
- Selenium supplementation: Ensure adequate selenium in the diet during the dry period, starting at least three weeks before the expected calving date. In selenium-deficient areas, this single intervention can dramatically reduce retention rates. Vitamin E works synergistically with selenium, though selenium alone showed a clear preventive effect in research.
- Calcium management: Subclinical low calcium after calving is far more common than full-blown milk fever, and it weakens both uterine contractions and immune function. Dietary strategies during the close-up dry period (like managing the balance of certain minerals in the feed) help cows maintain calcium levels through the calving transition.
- Minimize calving difficulty: Proper bull selection for heifer matings, adequate body condition at calving, and clean, low-stress calving environments all reduce the risk of difficult births that predispose to retained membranes.
- Body condition: Cows that are either too fat or too thin at calving are at higher risk. Targeting a body condition score of 3.0 to 3.5 (on a 5-point scale) at calving keeps metabolic stress manageable.
If your herd has a retained placenta rate above 5 to 8%, that signals a systemic management or nutritional issue worth investigating rather than treating cows one at a time after the fact.