Weight is the whole story
Every rabbit ages, but a Flemish Giant ages under far more load than most. Her size, once her glory, becomes the central fact of senior care: each hop lands heavily on joints and on the skin of her hocks, her spine carries a long, heavy frame, and getting up from rest takes visible effort. An older Giant may flop for longer stretches, choose one favourite corner and defend it by simply staying there, and lose interest in crossing a room she once patrolled. Read reluctance to move as information, not stubbornness.
A pen built like a padded room
House her entirely at ground level, in a pen large enough for full stretched-out rest and a few comfortable hops, floored with thick, non-slip mats or layered rugs over a solid surface. Slippery floors are a senior Giant's enemy, because a splayed hind leg under that much weight can injure a hip or spine. Remove ramps, stools, and anything she might still attempt to jump from. Use an oversized litter tray with a very low entry cut into one side, filled generously, and place hay racks or piles at resting height in more than one corner so eating never requires a journey. Water in a heavy crock she cannot tip, refreshed often, suits a big drinker better than a bottle she must crane for.
Feet, hocks, and nails under pressure
Check her hocks weekly: look for thinning fur, pink or broken skin, and swelling, and improve padding at her favourite resting spot the moment you see redness rather than waiting for a sore. Keep nails trimmed in small, frequent sessions, because long nails change how that heavy foot lands and add strain to toes and wrists. Inspect her underside and scent glands gently, clean any build-up you find with a damp cloth, and check her rear daily in warm weather, since a big rabbit who cannot groom her own bottom is at real risk from flies. Two people and a towel sling make these checks calmer and safer than one person wrestling a strong, heavy animal.
Hay first, weight watched, gut counted
Keep grass hay constantly available; it drives the gut movement and tooth wear a senior rabbit depends on, and it fills her without the calories that worsen joint load. Measure pellets rather than free-pouring them, favour leafy greens over sugary treats and fruit, and weigh or body-check her monthly by feeling ribs and spine under a light covering of flesh. In a Giant, droppings are easy to count, so do it: a clear drop in number or size across a day signals a slowing gut. A Flemish Giant who stops eating, produces almost nothing, sits hunched and grinding her teeth, or cannot rise comfortably needs a vet the same day, and hay and water should stay within reach while you arrange it.
Lifting rarely, and only with support
Avoid lifting a senior Giant whenever the job can be done at floor level, which, with planning, is nearly always. If she must be moved, use two people, support her chest and hindquarters together so her spine stays level, and keep her close to the ground over a soft surface. Never let her hindquarters dangle or twist free, because a kick from legs that powerful can injure her back.
Big rabbit, shared workload
A senior Giant generates real work: deep litter changes, mat washing, hay hauling, weekly foot checks that take two pairs of hands. Shared casually, the checks are the first thing to slip. KinsLe Care Teams lets a household assign those jobs by name, from hock checks to tray changes, with each completed task marked by a timestamp, so her care stays thorough even on the household's busiest week.