A sick mouse's cage should be cleaned thoroughly with a solution of a half-cup of chlorine bleach mixed with one half-gallon of water. All toys, tunnels and food bowls should be sanitized, and the mouse's bedding should be replaced.
Place the mouse in a safe location and remove all toys and dishes. Discard bedding or litter, wash the interior of the cage with hot, soapy water, and rinse thoroughly. After rinsing, spray the cage with a bleach and water solution. Let the solution remain on the cage for ten minutes, then rinse and allow the cage to dry. Water bottles, food dishes and toys can be soaked in a bleach solution for ten minutes to kill viral and bacterial contaminants.
To disinfect tunnels and other toys, disassemble the toys before washing to ensure all corners and crevices are sanitized. Use cotton-tipped swabs or toothpicks to remove debris from tight corners. Wooden and other porous items need to be soaked for a longer period of time to disinfect the items completely. Wooden toys, for instance, may be soaked in the bleach solution for up to twenty minutes and then rinsed and air dried before use. Add clean bedding or litter to the dried cage and return food dishes and water bottles after drying. Disinfect the mouse's cage several times a week until the illness has passed. After sanitizing the mouse's cage, disinfect the sink and other areas where the cage was cleaned to prevent the spread of bacteria.