Adopting an adult or rehomed lizard: an honest reality check

Quick answer

Taking on an adult or elderly lizard is usually taking on somebody else's husbandry history. Reptiles absorb years of small errors without complaining, and the damage shows up later as bone deformity, kidney disease, obesity or a mouth that will not heal.

What you are assessing is not just the animal. It is everything that has been done to it since it hatched.

That is not an argument against doing it. Rehomed lizards are frequently in real need, many of the problems are manageable, and reptiles respond well to correct conditions at any age. It is an argument for going in with a vet appointment booked, an honest expectation of what can and cannot be reversed, and a plan to rebuild the enclosure rather than inherit it.

The single most useful thing you can do is refuse to bring the old setup home. Whatever went wrong, the equipment is usually part of it, and the previous owner's lamp is not a bargain.

• Do not inherit the enclosure, the lamps or the substrate. Build a correct setup and move the animal into it.
• Metabolic bone disease leaves permanent deformity, but it can be stopped from progressing.
• Ages given by rehomers are usually estimates. Size and colour do not tell you an age.
• Book a reptile-experienced vet before the animal arrives, and expect radiographs and blood tests to be on the table.
• Lifespan varies enormously by species, from a few years to decades. Know which you are taking on.

Decide in 60 seconds

Why rehomed reptiles arrive damaged

A mammal that is cold, hungry or in pain tells you. A reptile does not. It slows down, it uses less energy, and it goes on looking broadly the same while its physiology quietly fails.

Ectothermy is the root of it. A lizard cannot generate its own body heat, so its digestion, immune function, healing and activity all run at the speed its environment permits. A tank a few degrees too cool does not produce an obviously sick animal; it produces an animal that digests poorly, mounts a weak immune response, and gradually loses condition over years.

That is why the standard rehoming story is so consistent. The animal was bought as a juvenile, the setup was assembled from a starter kit, the lamps were never replaced, the diet drifted, and nobody noticed anything for three years.

Four inherited problems dominate.

Metabolic bone disease.

Caused by inadequate ultraviolet B, inadequate dietary calcium, an unfavourable calcium to phosphorus ratio, or temperatures too low to allow normal metabolism. The body maintains blood calcium by taking it from the skeleton, and bone is replaced with fibrous tissue.

What you see: a soft or rubbery lower jaw, a jaw that will not close properly, bowed or thickened limbs, a kinked spine or tail, tremors, difficulty lifting the body off the ground, and in advanced cases fractures from ordinary movement.

What can be done: correct husbandry and veterinary treatment stop the progression and can strengthen what remains. The deformity that has already occurred does not straighten. An animal with a permanently altered jaw may need food prepared differently for life.

Obesity and fatty liver.

Very common in bearded dragons and leopard geckos fed heavily on high-fat feeder insects with no activity. Fat pads behind the head, a thick tail base, and a body that no longer narrows at the waist. Correcting it must be slow, because a reptile that loses weight rapidly mobilises fat into a liver that cannot keep up.

Chronic dehydration and renal disease.

From low humidity, no water source the animal recognises, a diet unsuited to the species, or long-term low-grade illness. Sunken eyes, wrinkled or tented skin, sticky mouth membranes, thick or discoloured urates, and eventually weight loss and lethargy. Gout, where urate crystals deposit in joints and organs, is a late consequence and is extremely painful.

Retained shed and skin damage.

Rings of old skin around toes, the tail tip and the spectacles of geckos, caused by inadequate humidity. Constricting bands cut off blood supply, and toes are lost. This is fixable, and it must not be fixed by pulling.

Ageing a lizard you know nothing about

You cannot do it reliably, and neither can anyone else.

Size does not equal age. A lizard kept cool and underfed grows slowly and stays small. One power-fed as a juvenile reaches adult size quickly and may be a year old.

Colour changes with shedding cycle, temperature, mood and lighting, not usefully with age.

Weak clues include reduced activity, cloudier eyes, a duller or rougher shed pattern, worn or missing toes and claws, and loss of muscle over the hips and tail base. Every one of those also has disease explanations, which is exactly why they are unreliable.

The practical approach is to ask for documentation: the date of purchase, the shop or breeder, any vet records, any weight history, and any photographs from the early years. Treat the stated age as an estimate, and plan around the animal's condition rather than its supposed birthday.

Lifespan matters here because it changes what you are committing to. Some chameleons are short-lived and an adult may have very little time left. Leopard geckos, crested geckos, blue-tongue skinks, tegus and green iguanas are long-lived, and an adult of one of those may still have a decade or more. Establish which species you are actually being offered before you agree to anything.

The questions to ask before you commit

The lamp question is the most revealing. Ultraviolet output declines steadily and is gone long before the lamp stops producing visible light. An owner who cannot tell you when the tube was last changed is telling you that it has not been changed, and that alone predicts a large share of what you will find.

Assess the animal in front of you

Posture and movement. It should lift its body clear of the floor when it walks, not drag its belly. Watch it move across the enclosure. Tremors, a wobble, a dragged limb or an inability to lift itself all matter.

The jaw. Gently feel along the lower jaw. It should be firm. Softness, swelling, or a jaw that does not close is metabolic bone disease until proven otherwise.

The limbs and spine. Look for bowing, thickening at the joints, kinks, and asymmetry.

Body condition. Look at the hips, the tail base and the ribs. Species differ, but a healthy animal is neither sharply angular nor rounded and bulging.

Eyes. Clear, open, not sunken. Sunken eyes point at dehydration.

Mouth. If it can be seen safely, look for redness, swelling, cheesy material or a bad smell. Do not force a mouth open.

Toes and tail tip. Count the toes. Look for constricting rings of old skin and for missing digits.

The vent. Clean, no swelling, no discharge, no stuck material.

Skin. Look for stuck shed, discoloured patches, and lumps.

Alertness. It should notice you. A completely unresponsive reptile is either far too cold or seriously ill.

Grip underfoot matters for an animal with weakened limbs. Smooth glass or plastic makes a mildly affected lizard look far worse.

Rebuild the setup, do not inherit it

This is the single decision with the biggest effect on outcome.

Replace the ultraviolet lamp with a new one of the correct type and strength for the species, at the correct distance, with nothing between it and the animal. Glass and most plastics block ultraviolet, so a lamp shining through a lid does nothing.

Provide a proper thermal gradient, measured with an infrared thermometer at the basking surface and with a separate reading at the cool end. Guessing is not measuring, and stick-on strip thermometers are not accurate enough for this.

Use a thermostat on every heat source.

Match humidity to the species, with a hygrometer, and provide a humid hide if the species uses one.

Choose the substrate deliberately, with impaction risk and the species' natural behaviour both in mind.

Add hides at both ends of the gradient, so the animal never has to choose between being the right temperature and feeling safe.

Lower the climbing structure for an older or weakened animal. Falls onto a hard floor injure reptiles with soft bones. Keep basking accessible with a gentle ramp rather than a leap.

Take nothing porous from the previous home. Wood, cork, substrate and used decor can carry mites and pathogens.

The first weeks

Quarantine. Keep the new animal completely separate from any other reptile, with separate equipment and hand washing between them, for a meaningful period. Reptile parasites and infections move easily and some are slow to appear.

Do not change everything at once. Keep the diet similar initially, then improve it gradually. A reptile that refuses a new food may simply stop eating.

Handle minimally. Let the animal settle. Rebuilding trust and rebuilding condition both take longer in reptiles than owners expect.

Weigh on arrival and then regularly, on a gram scale, and record it. This is the most useful single record you will keep.

Book the veterinary appointment for the first fortnight even if the animal looks fine. Ask for a faecal parasite screen, a body condition assessment, a look at the mouth, and a discussion of whether radiographs and blood tests are warranted given the history.

Watch how the animal carries its weight, whether it lifts clear of the floor, and whether the toes are all present and straight.

What can and cannot be reversed

Money, access and honesty

Reptile veterinary care is less widely available than small animal care, and finding a practice with genuine reptile experience is worth doing before you need one urgently.

Most useful investigation in a reptile involves radiographs, blood tests, or both, and some of it requires sedation. That is a real cost each time.

Equipment is a genuine expense as well. A correct enclosure with the right lamps, thermostats and measuring instruments costs more than the animal usually does, and the lamps are a recurring cost because they must be replaced on a schedule.

Decide, before you adopt, what you would fund. Then have that conversation with everyone in the household.

What never to do

Do not bring the old lamps, substrate or porous decor into your home.

Do not pull retained shed off toes, tails or eyes. Raise humidity, soak, and let it release.

Do not attempt to correct obesity quickly.

Do not house the new animal with an existing reptile, in either direction, before quarantine and a veterinary check.

Do not assume lethargy is age. In a reptile, lethargy is a temperature question first and an illness question second.

Do not rely on a stick-on strip thermometer or on the temperature printed on a heat mat packet.

Do not dose calcium, vitamins or any medication on your own judgement in an animal with suspected metabolic bone disease, since the balance of calcium, phosphorus and vitamin D matters and getting it wrong is possible in both directions.

Do not skip hand washing, especially in a household with young children, older adults or anyone immunocompromised.

When to get help

Contact a reptile-experienced vet the same day for an animal that is collapsed, having tremors or seizures, bleeding, unable to right itself, straining without producing anything, or has an obviously fractured limb.

Book an appointment within the first fortnight after adoption regardless of appearance, and sooner for a soft jaw, bowed limbs, swollen joints, a mouth that looks red or has material in it, sunken eyes, or constricting rings of retained shed.

Book promptly for weight loss, refusal to eat that persists once temperatures have been verified as correct, or a change in the colour and consistency of the urate portion of the droppings.

Correct heat, a working lamp, humidity that suits the species and hides at both ends. Most rehomed lizards improve substantially on that alone.

Bring the full history to the appointment: species, stated age and its source, the previous diet and supplements, the previous lighting and when it was last changed, measured temperatures and humidity from the old setup if you have them, the current weight, and your photographs. A reptile examination tells a vet a great deal, and the husbandry history usually tells them more.