The tegu signs that show up first
An aging Argentine tegu with joint discomfort usually changes how he walks before he changes how he eats. His normal confident patrol, body lifted clear of the ground on four powerful legs, becomes a shorter, lower stride. Hind toes may scrape the substrate at the end of each step, wearing those claws unevenly. He may plant one front leg carefully, as if testing it, and shift his considerable weight away from a sore knee or hip. After rest, especially after a cool night, the first minutes of movement can look wooden, then ease as he warms under his basking lamp.
Climbing, digging and the basking platform tell the story
A healthy adult tegu climbs onto his basking platform and digs with real enthusiasm, and an aging tegu who stops doing either is giving useful information. Hesitating at the platform edge, taking a lower basking spot, or sliding down instead of stepping down all suggest that lifting and lowering his body has become uncomfortable. Digging that stops after a few scrapes, or digging done entirely with one front leg while the other is held tucked, points the same way. Note which activity he quit: tegus rarely fake effort, so an abandoned favourite dig corner matters more than a single lazy afternoon.
What to watch on the legs themselves
Look closely at an aging tegu's joints during his soak, when he is calm and his legs are easy to see. Compare left and right knees, elbows, wrists and toes for puffiness or a knobbly, thickened outline on one side. Check whether a hind foot turns outward as he walks, and whether he flinches or pulls a leg away when it is gently handled during routine care. Photographing the same joint weekly, from the same angle, turns a vague feeling that a leg looks bigger into a comparison a vet can actually use.
Changes you can make while you observe
Lowering an aging tegu's basking platform and adding a wide, gentle ramp removes the jump-down landing that sore elbows and shoulders dislike most. A deeper patch of soft substrate in his dig area lets him exercise without striking hard flooring, and placing food and water on one level ends the need to climb for basics. Keep his floor warm and free of slick surfaces, because a heavy tegu who slips once will guard that leg for days. Avoid lifting him by a single limb during handling; support his full weight so no sore joint takes the strain alone.
When an aging tegu needs the vet promptly
Book a reptile vet promptly if an aging tegu stops bearing weight on a leg, if a joint swells noticeably over days, or if dragging toes start to wear raw. Sudden refusal to move at all, a leg held at an odd angle after a fall from a platform, or appetite loss alongside the stiffness all move the visit from routine to urgent. Bring your notes on which leg, which activity and when the change began, plus his weights and basking temperatures, because joint discomfort in a tegu shares signs with several other problems only an examination can separate. A dated record like that travels best inside KinsLe's Pet Passport, where his vet can open the whole mobility history at the appointment.