Keep the carrier available in a quiet, accessible place rather than bringing it out only when a stressful journey is imminent. Allow the cat to investigate voluntarily, with familiar bedding if suitable. Begin with small positive interactions and avoid shutting the door as soon as the cat first enters. Build progress gradually, noticing whether the cat remains relaxed. Practise only the steps it can manage comfortably, and seek advice if fear is strong or a visit is urgent. You may be able to train using the lower section first if the design allows safe removal of the top.
The aim is to reduce surprise, not trick the cat into confinement. Keep the carrier clean and inspect its fittings during this period. If the cat has a history of severe travel distress, contact your veterinary practice early so preparation can be tailored. Begin with the door secured open or removed where the design allows, so it cannot swing shut unexpectedly while the cat investigates.
For product comparisons alongside this advice, see Rolling pet carrier and 90 cm folding soft crate. The details below explain their sizes and uses.
Further reading: cats.org.uk; pdsa.org.uk; cats.org.uk.
Rolling pet carrier
90 cm folding soft crate