All water and soft food dishes must be washed out every day and frequently sterilized. A dish washing machine is best. The floor of the bird room is to be kept swept and mopped clean. Hand in hand with sanitation goes disease prevention and control. I write prevention and control because treatment is only to be done under a veterinarian's supervision.
All sick birds are to be isolated and professional assistance sought.
The shotgun approach of antibiotics, sulfa drugs, vitamins, and god only knows what else has killed as many birds as germs. All new stock must be quarantined. The cage and fixtures of a sick bird have to be well scrubbed and disinfected. All wooden items, like perches must be discarded. This may be dispensed by means of a hand held mister.