Start With a Floor He Can Trust
A rat whose hind legs are weakening drags his back feet more than he lifts them, and that changes what a safe floor looks like. Cover hard or cold flooring with fleece, a folded blanket or a washable mat, so his dragging toes glide instead of catching on edges and thresholds. Use a playpen with low sides he will not be tempted to scale, or block off a corner of the room: no sofa edges to fall from, no ramps up to furniture, no gaps he could wriggle into and then struggle to reverse out of. Get down and check the space at his height before each session, because the hazards that matter now — a trailing cable, a cold gap under a door, a single step down he used to hop without thinking — are all at floor level.
Enrichment That Happens in Front of His Paws
Weak hind legs do not dim a rat's curiosity, so bring the interesting things down to where his strength still is. Cardboard tunnels and low boxes laid flat become a ground-level maze he can push through using his front end. Scatter a portion of his normal food and a few prized treats through shredded paper or a dig box of safe bedding, so he forages by nose and forepaws rather than by climbing. A shallow, heavy dish of water with peas or sweetcorn pieces to fish out is a favourite senior-rat game: it asks for reach and coordination from the front half only, and the water stays shallow enough that a tired rat is never out of his depth in it. Rotate two or three of these activities each session so the same small space smells and feels new, and hide the treats in slightly different places so his nose, not his legs, does the travelling.
Short, Warm and Supervised Sessions
Little and often suits a rat with hind-leg weakness far better than one long expedition. Ten to twenty unhurried minutes, once or twice spread through the day, gives him movement, company and mental work without exhausting the front legs that now do most of the lifting. Sit inside the pen with him: for a senior rat, the owner is half the enrichment, and a familiar lap to rest against is a destination in itself. Keep the room warm and draught-free, because older rats feel the cold sooner and a chilled rat will simply stop moving. Return him to his cage while he is still bright and interested, rather than after he has gone quiet — finishing ahead of tiredness keeps floortime something he looks forward to tomorrow.
Watch the Feet, the Skin and the Spirit
Dragging feet wear nails unevenly and can rub the tops of the feet sore, so glance at them after every session: look for redness, broken skin, swelling or a nail catching on fabric. A rat who is coping well with his new limits will still hurry to the pen door, forage keenly and settle to sleep normally afterwards. Contact your vet if the weakness suddenly worsens instead of creeping, if sores appear on his feet, if he loses bladder control, stops eating or seems distressed rather than simply slow — gradual change is the expected shape of old age in a rat, but a sudden step-change deserves a professional look. Logging each floortime session in KinsLe's Care Teams, with a line about how he moved, builds a timestamped picture of his good and slower days that makes those changes far easier to judge.