If it's made of particle board like mine and ruined from drops of water getting on it I would replace it with a piece of plywood. I have also seen people use peel and stick tiles in their cabinets instead of contact paper. It looks nice and protects the wood.
Thank you for the information. You were right on point. I will use your method.
Is it the floor or cabinet bottom? If floor what is it made of?
Depending on what the issue is, you will probably have to remove the cabinet and cut out the area. Then put down new sub-flooring and re-position the cabinet.
There is a very thin plywood product that is easy to cut to size and nail down at the four corners and edges of the inside of a base cabinet, then paint or apply contact paper to match the cabinets.
Wood replace the wood and then something you could wash like a piece of linoleum.
Thanks to all that responded. All was very helpful and I will use suggestions. Thanks again