Check inside and close to home first, since stress often means hiding. Then lower the pressure at home so your cat has a reason to come back.
Look close first
Search as you would for any lost cat, starting inside the house and in the yards right next to it, and at the same time change things at home so your cat is not coming back to the same stress. A cat under pressure from a new kitten or baby may not have gone far at all. Humane World for Animals lists hiding and withdrawing among the signs of a stressed cat, so the cat you think left may be behind the water heater or under a neighbor’s deck. Check those places today. Then use the steps below to find out how it got out, reset its space, and share the work if you have a newborn at home.
What we know about the reason
We could not find any study showing that cats leave home because of a new kitten or baby, so be careful with the idea that your cat ran away from them. What is established is more limited. The ASPCA says some cats do not tolerate change well. Humane World lists hissing, withdrawing, hiding, loss of appetite and not acting normally as signs of stress around a new baby, and avoiding the newcomer as a sign of stress around a new cat. A stressed cat that is avoiding a new kitten could spend more time near doors or windows, and it is also true that a new arrival brings many more people through your front door. Either way, the practical plan is the same, and blaming yourself will not help you search.
Work out how it got out
New arrivals change how a home runs. Visitors bring gifts, strollers get wheeled in and out, deliveries pile up, windows get opened for air and tired people forget to latch things. Ask everyone who came by in the last few days which doors they used, and whether they saw the cat. If you have a door camera, go back through the footage. This tells you the time and the direction, and both are useful to anyone searching. Also check inside again, carefully. If you moved furniture for a nursery, there may be new gaps, and a cat avoiding a kitten may have picked a place you never look. Check the closets, behind the washer, in the basement and in any room that has been kept shut.
Reset the house for your cat
Your cat needs a reason to come back. Put its bowls, litter and bed back where they used to be if they were moved. Humane World advises keeping feeding, play and cuddle times steady, because predictability helps cats feel secure, and offering a retreat such as a quiet room or a cozy perch. If you have a new kitten, keep it in one room with its own food, litter and toys, and choose a room the older cat does not use much. That is the standard way to begin an introduction anyway. Also keep that room closed when you open outside doors. A curious kitten that gets out will give you a second search, so do not take it outside as a lure.
Tell helpers what they need to know
Give neighbors a short version. Say: Our cat Luna got out on Sunday. She has been stressed at home, so she may be hiding and may not come to us even if she hears us. Could you look in your garage, shed and under your deck? You do not need to mention the baby or kitten, though it may prompt people to offer help. Your flyer can say she is shy, and that people should call rather than try to catch her. Stressed or not, the basics do not change: report her to your shelter and vets, mark her as lost with the chip company, and put flyers on the closest doors. Our post on what to include in a missing-pet notice covers the wording.
If you have a newborn at home
Split the jobs by who can really do them. One adult who is recovering from a birth, or is up every two hours, should not be walking dark yards at midnight. Hand the night search and the door-knocking to a partner, relative or friend. Take the jobs that can be done from a couch: calling shelters and vets, posting in neighborhood groups, checking camera clips, making a list of streets. Do not take a baby along on a search at night. If a helper feeds your cat or looks after it, tell them the usual routine. The ASPCA points out that a cat may need time to adjust to a new caregiver, so a familiar voice is best for the final approach if you can manage it.
When your cat comes back
Do not bring it straight back into the same situation. Give it one quiet room of its own, and call your vet for a check, mentioning how long it was gone, whether it is eating and that it has been under stress. Then restart any kitten introduction from the first step. Humane World says the process can take days, weeks or months, that the cats set the pace, and that you should move on only when both are calm. With a baby, ask your vet about any health concerns from the cat’s time outside, and keep cribs off-limits as the ASPCA advises. Ask your vet or a qualified behaviorist if your cat keeps hiding, stops eating or changes its litter habits. Those can also be medical signs.
Sources
Humane World for Animals, introducing your pet to your new baby: humaneworld.org/en/resources/introducing-your-pet-your-new-baby. Humane World for Animals, introducing new cats: humaneworld.org/en/resources/how-introduce-your-new-cat-resident-cats. ASPCA, cats and babies: aspca.org/pet-care/cat-care/cats-and-babies.