Abstract: A modular kennel system, each module including a floor tub having a sloped floor and a gutter formed therein that is supported at a level above the surface on which the system rests for draining wastes therefrom. The system is erected on site without modification of the site in a variety of configurations and sizes and with or without a second level of enclosures. Each module comprising the system includes a substantially vertical panel from which the floor tub is supported and the drain basin formed in the gutter of the floor tub is connected through a plumbing trap to a drainpipe that runs between the module and the next adjacent module to connect the drain basins of the gutters from successive modules. This structure of the modular kennel system prevents cross-contamination, including sewer gases, between enclosures. The system may also include manual, timed, or conductivity-controlled flush systems for ridding the enclosures of waste fluids under a grate that is easy to clean.