Design around a cat who goes limp in your arms
A Ragdoll's famous flop is charming on the sofa and awkward at a carrier door: a relaxed, heavy cat cannot be guided in like a purposeful walker, and pushing a limp cat through a narrow front opening helps nobody. Choose a top-opening carrier as your first priority, so he can be lifted and lowered in with his body supported, and look for a design where the top half removes completely, letting the vet examine him in the base while he does his best impression of a cat who has nowhere to be. Wide front doors are the acceptable second choice; small round entrances are not.
Honest sizing for a large, slow-maturing breed
Ragdolls are among the larger breeds and keep growing well past their first birthday, so measure length and shoulder height and buy for the adult cat, with room to stand, turn and lie stretched on his side. Check the weight rating with genuine margin, because a big male Ragdoll tests flimsy bases simply by sitting down. The base should be rigid and stay level when lifted, since a sagging floor under a heavy, relaxed cat makes the whole carrier sway in a way that unsettles even this most laid-back of breeds on the move.
A firm, cushioned base for a cat who stays put
A Ragdoll will typically choose one spot and remain there for the journey, so the quality of what he is lying on matters more than for a restless breed. A firm cushion that supports without engulfing, covered in washable, low-pile fabric, over a non-slip and leak-proof base, is the right specification. His semi-long coat does not mat as readily as some, but a smooth interior still keeps him comfortable, and familiar bedding from his favourite chair carries the smell that tells a home-loving Ragdoll this box is an extension of his territory, not an exile from it.
Calm visibility and gentle ventilation
This breed bonds closely to its people and usually travels best able to see you, so choose a carrier with barred or mesh panels he can watch through, with the option of a light cover if a busy waiting room gets too much. Ventilation on several sides keeps a large, coated cat cool, and a quiet design helps too: carriers whose doors rattle and handles clank at every step startle a cat who otherwise takes travel in his stride. Belt the carrier flat in the car so his chosen position stays the position, rather than sliding with every turn of the road.
Practise the lift, not just the box
Leave the carrier out as a bed, let him claim it, and rehearse the actual sequence: the two-handed supported lift in through the top, the lid closing, the short carry to the car. A Ragdoll's trust is his great asset, and unhurried practice protects it far better than any feature on the carrier itself. For longer trips, a clip-on water dish and a scheduled pause in a locked car for tray access in a larger travel setup keep him comfortable. His vet history travelling in his KinsLe Pet Passport completes the picture for any clinic that meets this gentle cat.