Retained Placenta in a Queen: The 24-Hour Decision

A placenta left inside a queen is a 24-hour clock, not a wait-and-see. Count the placentas against the kittens within minutes of the last birth, because every kitten should deliver its own. If the count is short and no tissue appears within 24 hours, the queen needs an examination, not another day of observation. Foul discharge or a temperature above 39.5 C moves that timeline from days to hours.

Count placentas while the queen is still delivering

Each kitten arrives with its own placenta, and a queen often eats them, which is normal and makes counting hard. Put on gloves and take the soiled bedding away as each kitten is born so you can see what has passed. Write the numbers down: 4 kittens and 3 placentas means one is retained until proven otherwise. Uterine atony after a long labour, a large litter of 6 or more, or a single oversized kitten are the usual reasons a placenta stays behind. Queens that had a retained placenta in a previous litter carry a higher risk in the next one.

The 24-hour line

Medical help is reasonable to delay for 12 to 24 hours, because a placenta that is still in the uterus can pass on its own while the cervix is open. After 24 hours the tissue starts to break down, and the uterus becomes a culture dish. From hour 24 to hour 48 the queen may still look fine while a low-grade endometritis builds. Beyond 48 hours, expect fever, refusal to eat, and poor milk let-down, and expect the treatment options to narrow. A queen that is still straining 6 hours after the last kitten is a separate emergency: a kitten may be stuck, and that is radiography and surgery territory.

Fever and discharge: the two red flags

Normal lochia is reddish-brown and odourless to mildly metallic for 24 to 48 hours, and it tapers off over 7 to 10 days. Normal rectal temperature in a queen is 37.8 to 39.2 C, and it can sit at the top of that range for 24 hours after birth without meaning infection. A reading above 39.5 C, taken 12 hours or more after the last kitten, is the line most vets act on. Discharge that turns grey-green, brown-black, or smells rotten, especially with a closed cervix and a swelling belly, points to retained tissue and metritis. A queen that ignores her kittens, lies flat, and stops grooming is telling you the same thing before the thermometer does.

Ultrasound, not guesswork

Ultrasound is the tool that answers the question. A retained placenta shows as a thickened, irregular uterine wall with fluid in the lumen, and the same scan rules out a forgotten kitten, which a placenta count cannot do. Radiographs help only for bones and are useless for soft tissue, so do not accept an X-ray as the answer to a missing placenta. Most clinics combine the scan with a blood panel: a white cell count above 20,000 per microlitre or a left shift supports metritis, and a glucose under 80 mg/dL in a nursing queen suggests she is no longer compensating. Take the temperature at home before you drive in and write it down; stress in the car can push it up half a degree.

Prostaglandin, oxytocin, or surgery

Oxytocin at 0.5 to 2 IU intramuscularly, repeated once after 30 to 60 minutes, is the traditional first move, but it only works while the cervix is open and the tissue is intact — realistically in the first 12 to 24 hours. Given later, it can cause a tetanic contraction around a rotting placenta and make things worse. Prostaglandin F2 alpha is the more reliable medical route: dinoprost at 0.1 to 0.25 mg per kg subcutaneously every 12 to 24 hours, or cloprostenol at 1 to 2 micrograms per kg. Expect nesting, panting, cramping, and milk let-down within 20 minutes of the injection; the placenta usually passes in 24 to 48 hours. Surgery — an ovariohysterectomy — is the answer when the queen is septic, when the uterus feels thin or ruptured, when 48 hours of medical treatment has produced nothing, or when she is not needed for breeding. Cost sits at roughly 150 to 400 dollars for medical management with ultrasound and antibiotics, against 600 to 1,500 dollars for emergency surgery, which is worth pricing before the decision is forced — see the cost calculator.

Situation	Timing	First choice
Placenta count short, queen bright and eating	Under 12 hours	Wait, monitor temperature every 6 hours
Still retained, no fever	12 to 24 hours	Ultrasound, then oxytocin 0.5 to 2 IU or dinoprost
Fever 39.5 C or foul discharge	Any time	Ultrasound, antibiotics, prostaglandin, fluids
No response to prostaglandin	48 hours	Ovariohysterectomy
Collapse, pale gums, cold ears	Immediate	Emergency surgery and shock treatment

Aftercare for the next 14 days

Antibiotics run 7 to 14 days, and amoxicillin-clavulanate at 12.5 to 25 mg per kg twice daily is the common choice because it is compatible with nursing. Do not stop early because the discharge cleared on day 4. Check the queen's temperature once daily for 10 days, weigh her on day 3 and day 7, and watch milk supply, since mastitis is the other reason a queen stops feeding kittens. Expect a reddish-brown discharge for up to 10 days; a return of bright red bleeding or a bad smell means the uterus is not empty. Keep the litter box clean and change bedding twice daily for the first week.

What it means for the next mating

Skip at least one cycle. Endometritis from retained tissue lowers conception rates and raises the chance of resorption, and the uterine lining needs 2 to 3 months to recover. Most breeders plan the next mating 3 to 6 months later, after two normal heat cycles, and have the queen checked by ultrasound before they book a stud. A queen that retains a placenta twice should be retired from breeding; repeat retention usually signals a uterine problem that will recur. If you are rebuilding the schedule, heat cycle timing covers how to read the cycle, and stud cat management covers booking and infection control at the stud.

Your checklist for the first 48 hours

1. Count placentas against kittens and write both numbers down.
2. Take the queen's temperature at 6, 12, 24, and 48 hours; 39.5 C is the call line.
3. Look at the discharge every time you change bedding: colour and smell matter more than volume.
4. Book an ultrasound if the count is short at 24 hours, rather than starting oxytocin blind.
5. Plan the next mating no sooner than 3 months out, and only after a clean scan.

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