Upon entering our adoption program, each cat is placed in quarantine for a 14-day period. In the quarantine period, each cat or kitten is in a seperate sheeted off cage, seperate from the other cages. This will help stop the spread of any airborne virus they may have and each cat having its own litterbox ensures if one cat has worms or other parasites that it does not spread to another cat. We don't like putting them in cages but it is for the health of every cat that we do this. They are only in cages while they are quaratined and received medical care and once they get a clean bill of health, no more cage.
During the quarantine period, they are bathed with an anti-fungal shampoo (immediately upon intake), monitored for illness, health checked, dewormed, treated for fleas, tested for FeLV/FIV, sterilized, vaccinated, and microchipped. Once the quarantine period and all medical is complete, the cats are made available for adoption. The quarantine period helps us ensure the cats adopted out are very healthy cats.
But keeping them healthy is more than just the above. Every day is "Poop Watch 2009". One of the joys of being a rescue group. You can't dump those litterboxes until you've inspected the pooh! "Regular" poop makes us happy.
Cages and litterboxes are very thoroughly cleaned every day. And each week, everything in the cage is replaced with bleached and disinfected items - carriers, litterboxes, toys, bedding, food/water dishes, etc. and all cages are bleached. We use a lot of bleach here and it typically takes several hours each weekend to bleach all the carriers, litterboxes, etc. Most of the other stuff can be put in the washer (even the little brooms and dustpans we use to sweep the cages and all the cat toys).
It's a lot of work, but our kitties are healthy and they like everything always being nice and clean.