A queen that loses a litter after day 30 may show only a smear of brown discharge, or nothing at all. In a French database of 5,303 purebred queens and 9,063 matings, 8.4% of confirmed pregnancies failed to reach term, and 8.5% of 28,065 kittens were stillborn. Loss is common enough to plan for, and uncommon enough that one lost litter says little about the next.
Five outcomes, one dividing line
Breeders say miscarriage; clinicians sort the event by timing. Embryonic death, resorption, abortion, retention of a mummified or macerated fetus, and stillbirth are five different diagnoses. The dividing line is about day 30, when the placenta starts producing progesterone and fetal bones begin to mineralise. Before it, a dead embryo is absorbed with no outward sign. After it, the queen must expel something, and that is what owners see.
The timeline decides the name
| Outcome | Window | What the queen shows |
|---|---|---|
| Embryonic death | Day 0-14 | Nothing; the next pregnancy check is negative |
| Resorption | Day 15-30 | No discharge, normal appetite, belly stops growing |
| Abortion | Day 30-60 | Fluid or tissue, brown-red discharge, straining |
| Stillbirth | Day 60-70 | Kittens delivered dead at or near term |
Any kitten born before day 60 counts as stillborn, even if it was alive minutes earlier. Normal gestation runs 63-66 days from the progesterone rise, with a reported range of 56-69, so a litter on day 58 is early rather than slightly off schedule; our day-by-day gestation timeline shows what should be visible when.
How often it happens
The French study remains the largest published feline reproductive dataset: 5,303 queens of 45 breeds, 1,521 catteries, 2011 to 2014, recorded by breeders rather than referral hospitals.
| Measure | Result |
|---|---|
| Matings producing a pregnancy | 85.2% |
| Confirmed pregnancies that failed | 8.4% |
| Matings ending in a litter | 78% |
| Mean litter size | 4.0 kittens |
| Kittens stillborn | 8.5% |
| Kittens dying before weaning | 16.0% |
The 8.4% counts only queens already confirmed pregnant, so early deaths in queens that never tested positive are excluded. Observed loss is 8.4%; biological loss is higher.
Signs that mean call today
- Any bloody discharge between week 2 and week 8 - never normal.
- Brown, green, black or pus-like discharge at any stage.
- Rectal temperature above 39.4 C (103 F), shivering or hiding.
- Abdominal straining, crying, or a hard tense abdomen.
- Sudden loss of girth after day 35, or a retained fetus with a foul smell.
- No food for more than 12 hours in a pregnant queen.
Bring any passed tissue chilled, not frozen. Histopathology and culture of fetus and membranes is the single most useful test, and it can only be done once.
Causes: infection first
Viruses are the most commonly reported infectious cause of abortion in queens. Feline panleukopenia virus is the classic: early infection causes resorption or abortion, later infection causes cerebellar hypoplasia in surviving kittens. Feline leukaemia virus causes loss in viraemic queens; feline immunodeficiency virus, feline herpesvirus type 1 and feline coronavirus are also implicated. Toxoplasma gondii is less common but testable.
Uterine bacterial infection is uncommon in a healthy cat in a clean home. When it occurs - usually Escherichia coli, staphylococci or streptococci - the queen looks sick: fever, anorexia, depression and a fetid yellow-brown discharge. That is an emergency.
Causes: hormones, trauma and genes
Progesterone comes from the corpora lutea and, from about day 30, from the placenta. It rises through the first three weeks, plateaus, then falls after roughly five weeks. In dogs, a drop below 2-3 ng/mL for 24-48 hours reliably ends a pregnancy, and luteal failure is a real diagnosis. In queens the evidence is thinner: the placenta takes over earlier, and feline texts treat hypoluteoidism as a diagnosis of exclusion, with false pregnancy the more common look-alike. Supplementation exists, but it is a veterinary decision.
Other causes include trauma, certain drugs, congenital defects, chromosomal errors and inbreeding, which is linked to smaller litters. Obesity is separately associated with dystocia and more stillbirths, so body condition at mating matters.
What the vet will do
Ultrasound comes first (scan timing by day). Gestational chambers are visible from day 10 and fetal heart activity from day 16-17; a scan 7 days later separates a slow start from a dead pregnancy. Palpation is easiest on days 21-25 and unreliable after day 35. Radiography from day 37 counts skeletons and checks for retention. A relaxin test is reliable from day 29. Progesterone can be measured, but one value proves little; the 48-72 hour trend is what counts.
Expect FeLV/FIV testing, a vaginal swab for culture, and Toxoplasma serology if exposure was possible. A full abdominal ultrasound in the United States averages about USD 323, with most bills between USD 200 and USD 500; a pregnancy recheck usually sits at the low end.
Treatment and the next 48 hours
There is no safe home treatment. If fetuses remain in the uterus, a veterinarian may use prostaglandin F2 alpha or cabergoline to empty it; prostaglandin requires hospitalisation. Infection needs fluids and injectable antibiotics safe in pregnancy. Retained or macerated fetuses are surgical cases; a stillborn litter needs the checks in stillbirth management. Progesterone is reserved for a documented low value with a live fetus.
Watch for fever, foul discharge and depression for at least 48 hours. Mammary enlargement can follow an early loss and usually settles in 7-10 days; mastitis is the complication to catch.
Four checks before the next mating
- FeLV and FIV tests on both cats, repeated after any show or outside mating.
- Blood typing for A, B and AB; a type B queen with a type A tom risks neonatal isoerythrolysis.
- Breed screening: echocardiogram for HCM in Maine Coons and Ragdolls, plus DNA tests such as PKD where required.
- Vaccines and parasites: panleukopenia and respiratory vaccines before mating; one emodepside spot-on about 7 days before the due date cuts lactogenic roundworm transmission.
Then manage the environment: quarantine returning cats for 2-3 weeks and separate the pregnant queen for at least the last 2-3 weeks. Energy needs rise about 10% per week, with intake 25-50% above maintenance by term - see queen nutrition for the feeding schedule.
Prognosis after one loss
Most queens that lose a litter carry the next to term; 8.4% is a population average, not a verdict. Breed again after one normal oestrous cycle with the checks completed. Two consecutive losses, or a loss after day 45 with fever, justify a full workup including thyroid testing and uterine imaging.
This is not a substitute for veterinary care
A queen can resorb an entire litter and still eat, groom and jump onto the shelf. If you suspect a loss, the useful actions are an ultrasound within 24-48 hours, saving any tissue, and a temperature record. This article summarises published veterinary literature; it does not replace an examination, and drug decisions belong to the veterinarian who has seen the cat.
Terms mentioned in this article
Frequently asked
Can a cat resorb a kitten without showing any signs?
Yes. Loss before about day 30 usually ends in resorption, with no vulvar discharge and no change in appetite or behaviour. It is normally found only because an earlier ultrasound showed a pregnancy that a later scan no longer sees. A queen can resorb one fetus and carry the rest to term.
Does one miscarriage mean the queen cannot be bred again?
No. In the French dataset of 5,303 queens, 8.4% of confirmed pregnancies failed, yet 78% of all matings still produced a litter. Most queens that lose one litter conceive and carry the next normally. Two consecutive losses, or a loss after day 45 with fever, justify a full workup.
Is a small amount of bleeding normal during cat pregnancy?
No. Any haemorrhagic vulvar discharge between week 2 and week 8 of gestation is abnormal and warrants an ultrasound within 24 to 48 hours. Brown, green or pus-like discharge is abnormal at any stage and raises the possibility of uterine infection or a retained fetus.
Related guides
- Pregnancy Diagnosis: Ultrasound at Day 21, X-Ray at Day 55
- Pregnancy Imaging: Day 21 Ultrasound to Day 55 X-Ray
- Cat Pregnancy Timeline: The 63 Days From Mating to Birth
- Cattery Disinfectant: 3 Classes, 1:32, 10 Minutes
- Cattery Hygiene: 1:32 Bleach, 30-Second Hands
- Colostrum Window: 24 Hours and 3 Records per Kitten