Abstract: This modular animal toilet assembly system has portable components, and is flushed by various fluids, gravity, flush valve, and air pressure means to public sewage systems, slurry or septic tanks. Some of the fluids include: water, oil, alcohol, anti-freeze, but are not limited to these. It can discharge into waste disposal means, such as, composting, incinerating, dehydrating, recycling or chemical or mechanical treatment. System components share, standardized, connectable, interfaces. Portable components include: toilet bowl fixture, having drainpipe trap, trap door, or sealing means; animal support platforms, having inserts with variously-shaped apertures, through which wastes pass; pipes for fluid intake and outlet. Platforms with inserts support various animals, while allowing animal waste to pass through apertures via gravity and flushing. Activators for flushing include: manual lever and animal-activated means, such as pressure-activated hydraulic system and photoelectric solenoid sensor system.