Is it permissible to sell expired pet food designated for disposal, without the administration's knowledge, and share the proceeds with the workers, or is this forbidden and impermissible?

If the food can be utilized without harm, then it should not be destroyed, as the Prophet prohibited wasting money. The permissibility of selling this food without the company's permission depends on the company no longer needing it, declaring it permissible, and there being no harm in consuming it. If explicit or implicit permission is given and there is no harm, then it is permissible to sell it and own its price. Specialists are to be relied upon to determine harm.