Start a Flemish Giant introduction behind a barrier
A Flemish Giant rabbit meets a resident pet first through a barrier, never nose to nose on open floor. Set a strong exercise pen or pet gate in a neutral room, because a Flemish Giant is a large, heavy rabbit that can injure itself scrambling away and can thump hard enough to escalate a tense dog. Place the rabbit inside the pen with a cardboard hide, hay and water, then bring the resident pet to the outside of the barrier on a leash or harness if it is a dog, or simply into the room if it is a calm cat. Keep this first session short. The goal is shared air and scent with no contact, and it ends while both animals are still relaxed, not after curiosity tips into fixation.
Read the giant rabbit and the resident in parallel
Body language decides when a Flemish Giant introduction moves forward. On the rabbit side, eating hay in the pen, grooming, or lying with legs stretched sideways signals settling; frozen stillness, repeated thumping, ears pinned flat or charging the bars signals the session should end. On the resident side, a dog that glances at the pen then looks back at you for a treat is coping, while hard staring, whining, lunging or ignoring recall is not ready for more. A resident cat that watches from a distance and turns away is giving good information too. Repeat barrier sessions over several days, swapping which side of the room each animal starts from, and let scent do quiet work by exchanging a cloth rubbed on each animal's cheek area between sessions.
Progress to shared floor time with exits open
Shared floor time for a Flemish Giant comes only after several calm barrier sessions. Choose the same neutral room, rabbit-proof the edges, and give the rabbit at least two hides and a clear run-back route to its pen, left open. The resident dog stays leashed with a second person handling the leash so the rabbit's handler can watch only the rabbit. Let the Flemish Giant choose whether to approach; a confident giant may hop over to investigate, and that choice matters more than any timetable. Keep sessions brief, scatter hay and leafy greens so both animals associate the room with foraging rather than staring, and separate them again before either tires. A resident rabbit, if that is the pairing, needs its own neutral-space plan and should never simply be placed inside the newcomer's pen.
Setbacks, supervision and the long game
A Flemish Giant introduction is not finished after one peaceful afternoon. Supervise every shared session for weeks, house the animals separately when nobody is present, and expect a setback if the resident pet's routine changes or a visiting dog raises the household tempo. Chasing, even once and even in play from a dog's perspective, resets the process back to barrier work, because a rabbit of this size bolting into furniture can be badly hurt. Keep feeding and resting areas permanently separate so neither animal has to defend resources. Assign barrier sessions, leash duty and pen checks to different household helpers in KinsLe through Care Teams, with each completed session marked off, so the Flemish Giant's introductions stay patient and identical whoever runs them.