First, I would not just get another rabbit to put in the cage. There is still a lot to be learned about pasturella and transmission, etc. It is thought by some that all rabbits may harbor it but only some become ill from it. Second, outdoor rabbits are under more stress which makes them more prone to illness. Now, There are different strains of pasturella. The hutch should be thoroughly disinfected with a bleach and water solution (1 part bleach to ten parts water – for example, 1 cup of plain household bleach to 10 cups of water). Then rinse extrememly well. I would also get new feeding crocks for your new rabbit. Proper management of a rabbit (proper cleaning, nutrition, etc) can help reduce the chance of a pasturella outbreak. Not all rabbits harboring the bacteria will even get sick – but there are MANY factors that determine if the rabbit will get ill or not. If you clean the hucth well, wait a few weeks, get new bowls and such. Clean out any hay used as bedding daily and replace with new, feed a quality diet, ideally keep the rabbit indoors to reduce the physical stress of living outside (and even mental stress if there are loose animals, racoons, etc in your area), and buy a rabbit that looks healthy (no younger than eight weeks of age, bright eyes, no signs of lumps or abcesses as pasturella can develop into these as well as the more common "snuffles", one with a glossy and smooth coat) and avoid a pet shop completely (over crowding of rabbits can increase the chance of pasturella becoming active and often bunnies at pet shops are taken at six weeks so they are cuter and often from less than stellar breeder or may have even been shipped hundreds of miles from a mill breeding facility) or breeder that houses rabbits close together and does not practice proper cleanliness or management, then you stand a better chance of getting a healthier bunny. And also, consider a rescue.