One placenta per kitten, out within 15 minutes of that kitten, is the pattern worth watching. Most queens pass the afterbirth 5 to 15 minutes after a birth, sometimes two in a row after a short pause. The number that turns a messy morning into an emergency is 24: a placenta still inside after 24 hours raises the risk of uterine infection and fever, and at that point the queen needs a temperature reading and an ultrasound, not another night of watching.
The 15-minute pattern
Stage two labor delivers a kitten, then stage three delivers its placenta, and the two alternate. A queen that produces a kitten at 02:10 should pass a placenta by about 02:25. If nothing appears within 30 minutes of the last kitten, stop watching the clock and start counting what you have. A placenta can also arrive after the next kitten, so a gap of 1 placenta at minute 30 is not automatically a retention, but a gap that is still there at minute 60 is.
Placentas are not always visible. Many queens eat them within seconds, which is normal and not a sign of a problem, but it destroys your count. Sit close enough to see what is delivered, and write down 2 columns on a sheet of paper: kitten time, placenta time. Breeders who do this catch a missing placenta in 20 minutes instead of discovering it at hour 30 when the queen is febrile.
Counting placentas against kittens
A litter of 4 should yield 4 placentas, but the count is allowed to be 1 short. Two placentas occasionally fuse into a single mass, and 1 kitten can be born with a shared afterbirth, so 3 placentas for 4 kittens can be normal. The reverse is never normal: 5 placentas for 4 kittens means one kitten is unaccounted for, which is far more serious than a retained placenta and needs a clinic visit the same day.
The 24-hour line and the fever signal
A normal queen sits between 38.1 and 39.2 °C. Take her temperature every 8 hours for the first 48 hours after the last kitten, using the same thermometer and the same technique, and write the numbers down. A single reading above 39.5 °C is a reason to call. So is a reading below 37.5 °C, which in a postpartum queen can signal exhaustion or infection rather than a normal dip.
Fever is not the only marker and often is not the first one. A queen with retained tissue typically shows 1 or more of these between hour 12 and hour 48: she stops eating, her breathing rate climbs above 40 per minute at rest, the discharge changes smell, or she lies flat and ignores the kittens. Any 2 of those 4 findings together justify a same-day visit, even with a normal temperature.
Discharge you should and should not see
For 24 to 48 hours after birth, a red-brown to dark green discharge is expected and needs no treatment. What is not expected: discharge that smells foul rather than metallic, discharge that is still dark green at day 4, bright red bleeding that continues past 10 minutes, or tissue hanging from the vulva. Do not pull on tissue that is visible. A placenta that is partly out and partly in can tear, and a torn piece left behind is harder to clear than a whole one.
Ultrasound at 24 to 48 hours
An ultrasound is the right recheck, and a radiograph is the wrong one. X-rays show mineralized kitten skeletons, not soft placental tissue, so a film taken after the last kitten tells you the uterus is empty of kittens while saying nothing about what else is inside. A sonographer looks for a thickened uterine wall, fluid with internal echoes, and retained tissue as an echogenic mass. Most vets recheck at 24 to 48 hours when the count is short and the queen is off her food, and repeat at 72 hours if the first scan was equivocal.
What not to do at home
No pulling, no vaginal flushing, no human medication, and no uterine-contracting drug unless a veterinarian has examined the queen and chosen the product and the amount. Oxytocin given to a queen with a kitten still in the canal, or with a closed cervix, can do real harm, and the dose is not a number to guess from a forum. Antibiotics are a decision for the vet who has felt the uterus, not a precaution to start because the morning looked messy.
The timeline that decides the case
| Window | Placentas | Queen temp | Resting breaths | Action |
|---|---|---|---|---|
| 0-15 min | 1 per kitten | 38.1-39.2 °C | Under 60 per min | Record both times |
| 15-30 min | 1 per kitten, 1 short allowed | 38.1-39.2 °C | Under 50 per min | Keep counting, note the gap |
| 30-60 min | 0 missing | 38.1-39.2 °C | Under 50 per min | Phone the clinic if still short |
| 12-24 h | 0 retained on scan | 38.1-39.2 °C | Under 40 per min | Book the ultrasound |
| 24-72 h | 0 retained on scan | Under 39.5 °C | Under 40 per min | Visit if the count stays short |
Cost, and why the early call is cheaper
An exam plus ultrasound runs $90 to $200 at most clinics, and a course of treatment adds $60 to $150. A queen that arrives at hour 60 with a fever, dehydration, and a uterus full of retained tissue costs $400 to $900 and may lose the uterus. The cost tables list the emergency side of that range, and the gap between the two columns is the argument for calling at hour 30 rather than hour 50.
Prevention starts before the mating
Retention is more common after long or difficult labors, after a large litter, and in queens with poor body condition at birth. Nothing guarantees it will not happen, but the risk is cheaper to manage when the queen enters pregnancy at body condition 5 out of 9, vaccinated, and screened for the inherited problems that make a cesarean more likely. Screening before the mating is covered in pre-breeding genetic tests.
What to write in the litter record
- Time of every kitten and every placenta, on one sheet, in 2 columns.
- Temperature at 0, 8, 16, 24, and 48 hours after the last kitten.
- Whether each placenta was seen, eaten, or missing.
- Discharge color and smell at 12, 24, and 48 hours.
- The phone number of a clinic that will see a queen at 3 a.m.
The full clinical picture of the condition, including how a partial retention differs from a complete one, sits in retained placenta in queens. Read it before the litter is due, not after.
Frequently asked
How long can a placenta stay inside before it becomes dangerous?
Twenty-four hours is the line most veterinarians work from. Within the first hour a missing placenta is a thing to watch and count; by 24 hours the risk of uterine infection and fever is high enough that the queen needs a temperature check and an ultrasound rather than more waiting. A short count that persists at 48 to 72 hours usually means a recheck scan and possibly treatment.
My queen ate the placentas, so I have no count. What now?
Switch from counting placentas to counting kittens and watching behavior. Write down each kitten time, take the queen temperature every 8 hours for 48 hours, and watch appetite, resting breathing rate, and discharge smell. Two of those four going wrong in a queen with an unknown count is enough reason for a same-day ultrasound, which shows retained tissue that a radiograph cannot.
Should I give a uterine-contracting drug at home?
No. Those drugs are a veterinary decision because they can cause harm when a kitten is still in the canal or the cervix is closed, and the amount depends on the queen weight, the stage of labor, and what the vet finds on examination. Human medication and vaginal flushing carry the same problem. If the placenta is missing at 30 to 60 minutes, the useful action is a phone call, not a syringe.