21 days is the shortest quarantine that covers the incubation windows a cattery actually faces: feline panleukopenia at 2 to 14 days, upper respiratory virus at 2 to 10 days, ringworm culture at 7 to 21 days, and feline leukemia virus antigen detection that can lag exposure by 30 days. A 14-day quarantine releases a cat while half those windows are still open.
The rule that matters more than the length: quarantine is a separate air space with separate utensils, not a cage in the kitten room. One shared food bowl undoes 20 days of separation.
What 21 days is built from
Line up 4 numbers and the 21 becomes obvious. FPV sheds in stool for up to 6 weeks and survives in a room for a year or more, resistant to most common disinfectants. FeLV needs 2 negative antigen tests 21 to 30 days apart in an exposed cat. Calicivirus and herpesvirus show up in 2 to 10 days but can be carried asymptomatically for months. Dermatophyte culture takes 14 to 21 days to turn positive.
So the calendar is: day 0 test and isolate, day 7 look for shedding, day 14 repeat the physical and start ringworm culture if any lesion, day 21 repeat FeLV and release only if everything is negative.
The room: 4 physical requirements
- A door that closes, in a room no other cat enters, at least 1.5 m from the nearest resident cat.
- Separate air: no shared return duct, no recirculating unit that serves both sides. A window that opens 5 cm, or a HEPA unit inside the room, is the practical minimum.
- A hand-wash station at the threshold: soap, 30 seconds, paper towels, and a bin inside the room.
- Dedicated kit: 1 scoop, 1 bowl set, 1 litter tray, 1 thermometer, 1 scale, 1 apron or change of clothes, all stored inside.
Traffic order is part of the protocol: resident cats first, quarantine last, always. Shoes stay outside the door. Litter is bagged inside the room and goes to the bin without passing through the kitten area.
The day 0, 7, 14, 21 checks
Weigh on the same scale at the same hour, before the first meal. Temperature is rectal with a digital thermometer, 30 seconds. Stool is scored 1 to 7, where 1 is hard pellets and 7 is liquid.
| Day | Weight (kg) | Temp (°C) | Appetite (% of ration) | Stool score (1-7) | Test or action |
|---|---|---|---|---|---|
| 0 | 2.8 | 38.6 | 100 | 3 | SNAP FeLV/FIV, fecal float, isolate |
| 3 | 2.85 | 38.5 | 95 | 4 | Weight check only |
| 7 | 2.95 | 38.6 | 100 | 3 | URI check, eye and mouth exam |
| 14 | 3.05 | 38.7 | 100 | 3 | Ringworm lamp, ear swab, dental look |
| 18 | 3.1 | 38.6 | 100 | 2 | FeLV repeat if exposure risk |
| 21 | 3.2 | 38.6 | 100 | 3 | Full exam, release decision |
Two weigh-ins down in a row, or a stool score of 6 or 7 for 2 days, resets the clock by 7 days. A kitten under 6 months that loses 5% of body weight in 48 hours is a vet call, not a wait.
Disinfection that matches the pathogen
Bleach diluted 1:32 from household strength, about 0.16% hypochlorite, with 10 minutes of wet contact, handles most surfaces but not FPV. For parvo-risk rooms use accelerated hydrogen peroxide or a labeled virucidal product, and plan 2 rounds 24 hours apart. Cat trees, cardboard and rope toys cannot be disinfected; they go out with the litter.
Bedding washes at 60°C for 30 minutes. Food bowls go through a dishwasher at 65°C or are soaked 10 minutes in the diluted bleach, then air-dried. Most cleaning failures trace to 1 reused sponge.
FeLV and FPV: the timing that trips people up
A negative SNAP test at day 0 does not mean the cat is negative. In an exposed cat, antigen can appear up to 30 days after exposure, so the test is repeated on day 21 to 30, and again at 60 days if the cat came from a known positive household. A positive result in a healthy cat is confirmed with a second method before any decision: see the isolation and testing sequence in contract terms.
FPV is the opposite problem: the virus is everywhere in the environment. Vaccinate at least 2 doses, 3 to 4 weeks apart, with the second dose 7 or more days before arrival. A kitten arriving at 9 weeks with 1 dose has a real gap, and the quarantine room is what covers it.
Release and the first 7 days after
Release on day 21 requires 4 green lights: 2 negative FeLV tests 21 days apart (or 1 plus a documented low-risk origin), no URI signs for 7 days, 3 consecutive weigh-ins up, and a stool score of 4 or lower. If any 1 fails, extend by 7 days rather than gamble.
Integration is not a door opening. Days 14 to 18: swap bedding for scent, 15 minutes a day. Day 21: feed on opposite sides of a gate, 2 m apart, for 3 days. Day 24: 10-minute supervised meetings, 1 per day, ending before either cat flattens its ears. Most catteries need 3 to 7 days of this before free access.
Track the new cat's weight weekly for the first 6 weeks against a growth chart: kitten weight tool. A flat line at week 2 is the earliest sign that something was carried in.
When to call the vet
- Temperature at or above 39.5°C, or below 37.5°C.
- No food for 24 hours, or 5% weight loss in 48 hours in a kitten.
- Stool score of 6 or 7 for 2 days, or any blood in stool.
- 1 sneeze cluster of 5 or more in an hour, or eye discharge.
- Any circular hairless lesion, or a positive ringworm culture.
- Positive FeLV or FPV antigen test, or a positive SNAP in a cat under 6 months.
Any 1 of these means the animal does not leave quarantine and the vet comes to the room, or the cat travels in a covered carrier wiped down on exit.
The 21 days as a checklist
- Day 0: isolate, weigh, temperature, SNAP test, fecal, photograph the cat's face and body for baseline lesions.
- Day 1 to 6: 2 checks a day, log 6 numbers, feed and clean quarantine last, every time.
- Day 7: physical exam, URI check, first weight trend review.
- Day 14: repeat exam, ringworm lamp, start culture on any lesion, scent swap begins.
- Day 18 to 21: repeat FeLV, decide release on 4 green lights, then gate-feed for 3 days.
One 21-day quarantine costs 3 weeks of a spare room and about 30 minutes a day. A panleukopenia outbreak in a 12-cat cattery costs 6 to 10 weeks, most of the litter, and the reputation that sells the next one. Breeders who keep this protocol rarely need to explain either number. A first litter planned under the same rules is covered in breeding age and first litter.
Terms mentioned in this article
Frequently asked
Why 21 days and not 14?
Because 14 days releases the cat while several windows are still open: FPV incubates 2 to 14 days, respiratory virus 2 to 10 days, ringworm culture needs 7 to 21 days, and FeLV antigen can lag exposure by 30 days. Day 21 allows a second FeLV test and a full ringworm culture read before any contact with residents.
Can the new cat share a room if it stays in a cage?
No. A cage in a shared room shares air, dust and hands, and one reused scoop or bowl defeats the separation. Quarantine needs a closing door in a room no resident cat enters, at least 1.5 m from the nearest cat, its own air path, its own bowls, litter tray and thermometer, and a hand-wash station at the threshold.
What if the FeLV test is negative on day 0?
That is a starting point, not a clearance. In an exposed cat, antigen may not appear for 30 days, so the test is repeated on day 21 to 30 and again at 60 days if the origin was a known positive household. Release needs 2 negative results 21 days apart plus no respiratory signs for 7 days and 3 rising weigh-ins.