A big lizard slowing down
Everything about iguana ageing is scaled up. The animal that once scrambled up branches and tail-whipped first and thought later now hauls a heavy body with stiffer joints, chooses the broad shelf over the high branch, and treats basking as the main event of the day. Muscle fades along the tail base and thighs, the jaw can look less full, and old injuries or worn toe joints from years of climbing may start to limit grip. An older iguana is also often calmer to handle — one of the genuine pleasures of the senior years — but calm should never be read as comfort without checking the rest of the picture.
Making the enclosure easier to climb
Redesign for descent as much as ascent, because falls injure old iguanas. Replace steep or narrow climbing routes with wide, gently sloped ramps covered in a grippy surface, lower the main basking shelf, and pad or clear the floor beneath favourite routes. Keep food and water reachable without a climb, so a stiff iguana never has to choose between hunger and effort. Check toes and claws regularly — worn, cracked or missing claws change how the animal grips — and keep basking temperatures at the normal adult level, since an old iguana that cannot get properly warm digests poorly and fades quietly.
Calcium, kidneys and appetite
The two organs of worry in a senior iguana are the kidneys and the skeleton, and both are fed or failed by the same daily routine. Keep the diet leafy and varied — dark leafy greens as the bulk, vegetables and a little fruit around them — with calcium dusting a habit, not an event, and UVB lighting replaced on schedule, because decades of marginal calcium is how older iguanas arrive at soft bones. Hydration protects the kidneys: mist daily, offer regular lukewarm soaks, serve greens wet, and learn your iguana's normal drinking so a drop-off registers. Appetite changes in an older female also deserve respect, since unmated females can still produce eggs and struggle to lay them.
Vet care for an older iguana
A senior iguana belongs on at least an annual vet schedule, ideally with periodic bloodwork, because kidney decline — the commonest quiet killer in this species — shows in blood values long before it shows in behaviour. Book promptly for appetite loss lasting beyond a few days, straining or a swollen abdomen in a female, tremors or weak limbs, a jaw that feels soft, or swelling around the joints. Bring weights and notes; with an animal this large and this slow to change, the trend across visits tells the vet more than any single day can.
Twenty years of an iguana is a filing cabinet of blood results, weights and enclosure changes, so keep it as one story: a KinsLe Pet Passport holds the records together in a portable packet, ready for the vet visits that matter more with every year.