The fostering agreement may decide for you
Most boarding advice assumes one owner and one cat, free to go anywhere. A foster household is different. The rescue you foster for usually keeps legal responsibility for its cats, and foster agreements commonly require the cat to remain at your address, to be cared for only by approved people, or to return to the rescue rather than enter commercial boarding. So the first step is not comparing catteries at all — it is re-reading your agreement and asking the rescue coordinator what cover they expect when you travel. Many rescues prefer to place the foster cat with another approved fosterer during your trip, which solves the problem inside their own network. If no foster cat happens to be in residence when you travel, the restriction lifts and the choice becomes about your own cat alone.
Why a sitter often fits the foster rhythm
When a foster cat is staying and the rescue agrees to home cover, a visiting sitter is usually the only practical shape of care. Foster cats are often mid-settling, mid-treatment, or mid-assessment for rehoming, and moving them to a cattery — even where licensing allowed it — would undo careful settling and expose them to a building full of unfamiliar cats. A sitter experienced with foster homes understands the particulars: separate feeding where cats are kept apart, litter trays in more than one room, medication or socialisation routines recorded for the rescue, and no assumption that the shy cat in the spare room may be picked up or let out. That specialism is rarer than ordinary pet sitting, so finding the right person matters more than the headline price.
The infection question cuts both ways
Foster households already manage a biosecurity juggle, because each new arrival can bring respiratory infections or parasites into the home. Boarding your own resident cat at a cattery adds another exposure route: your cat shares airspace and staff hands with many unfamiliar cats, then returns to a home where a vulnerable foster — perhaps a kitten or a cat recovering from illness — may arrive days later. Ask any cattery how they isolate new arrivals, what vaccination proof they demand from every boarder, and how pens are disinfected between residents. At home, ask the sitter to follow the same hand-washing and feeding-order discipline you use yourself, dealing with your resident cat before the foster, so your travel does not quietly break the hygiene routine that keeps the rotation healthy.
Timing your trip around the rotation
Foster carers have a lever other owners lack: the calendar. If your travel dates are flexible, planning trips for the natural gaps between placements removes the hardest version of this problem entirely — no foster cat in residence, no rescue permission needed, and your own cat can board or stay home on its merits. Where dates are fixed, tell the rescue early rather than the week before; coordinators can often hold off placing a new cat with you until you return, or schedule a short-stay foster that leaves before you go. The worst outcome is a new, unsettled foster arriving days before your departure, leaving a sitter to manage introductions you should have handled yourself.
Find carers who understand fostering
Generalist listings rarely reveal whether a sitter has worked in a multi-cat, changing household or whether a cattery will even discuss rescue arrangements. KinsLe's Pet Services Directory lets you find local pet businesses and sitters and connect with them directly, so you can put the foster-specific questions — rescue permission, separation routines, hygiene discipline, shy-cat handling — to real candidates near you and build a small bench of cover that understands how your household actually works.