Lizard seizures and tremors: what to do during the episode

Quick answer

During the episode itself there is very little to do, and most of what owners instinctively try makes it worse. Do not hold the lizard, do not put anything in its mouth, and do not try to straighten it out. Make the space around it safe, switch off the basking lamp so it cannot burn itself, dim the lights, and film it.

The work happens afterwards. A seizure in a pet lizard is almost never idiopathic. It is usually a calcium problem, a temperature problem, a poison, or an organ failing, and all four are found by measuring things rather than by watching the animal.

After an episode the lizard goes somewhere flat, padded, escape-proof and free of anything it can fall from.

• Do not restrain a seizing lizard. Restraint causes fractures, especially in an animal with weak bones.
• Never put a finger, a spoon or anything else in the mouth. Reptiles cannot swallow the tongue.
• Turn the heat lamp off during the episode so a thrashing animal cannot press against it.
• Film it and time it. That video is worth more than any description.
• Measure the enclosure temperature immediately afterwards. Overheating is a common and reversible cause.

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Repeated or continuous seizures are an emergency.

A single short episode in an otherwise well lizard needs a same-day appointment. More than one episode within a day, an episode that does not stop within a few minutes, or a lizard that does not regain normal posture between episodes needs emergency care immediately. Prolonged seizure activity damages the brain, exhausts glucose reserves and raises body temperature dangerously, and it is treated with drugs that are not available at home.
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Decide in 60 seconds

What a seizure looks like in a lizard

A reptile does not have the layered cerebral cortex a mammal has, so the picture is less familiar.

Early or partial activity shows as fine, rippling twitches, most obvious in the toes, along the limbs and around the jaw. Owners often describe it as trembling or shivering. In a lizard, shivering is not a normal thermoregulatory behaviour, so it should never be dismissed as feeling cold.

Full episodes involve rigid extension of the limbs and neck, arching of the back, paddling, rolling or spinning, and a loss of the righting reflex. Some lizards vocalise. Some gape. The animal is not aware of you and will not respond to being spoken to.

Star-gazing, in which the animal holds its head up and back and stares upward as if fixed on something, is a related neurological sign rather than a seizure. It appears with several of the same causes.

Afterwards, a lizard is usually flat, dull, disorientated, and slow to move. That period can last minutes or hours.

Why it happens

Low blood calcium.

This is the commonest cause in young, fast-growing pet lizards, particularly bearded dragons, veiled chameleons, water dragons and green iguanas.

Calcium stabilises nerve and muscle membranes. When ionised calcium in the blood drops, those membranes become leaky and fire on their own, which is why the earliest sign is a tremor rather than a collapse. As it worsens, the tremor becomes tetany and then a generalised seizure.

The reason it drops is almost always husbandry. Reptiles need ultraviolet B light to synthesise vitamin D3, and without D3 they cannot absorb dietary calcium at all. Feeder insects are naturally low in calcium and high in phosphorus, which makes the balance worse. A lizard under an old or wrongly placed ultraviolet lamp, fed undusted insects, is drawing calcium out of its own skeleton to keep its blood level up, and eventually there is nothing left to draw on.

Look for the companion signs: a soft or rubbery lower jaw, swollen limbs, a kinked spine or tail, difficulty lifting the belly off the ground, and reluctance to climb.

Overheating.

A failed thermostat, a lamp that has fallen, a viv in direct sun, or a heat mat under glass. An overheating reptile becomes frantic, gapes, presses at the glass, and then becomes uncoordinated and collapses. This one is reversible if it is recognised, which is why the first thing to do after any episode is to measure the enclosure.

Poisoning.

Household insecticides, fly sprays, flea products used on other pets in the same room, aerosol cleaners, essential oil diffusers, treated wood and fumigation all cause tremors and seizures in reptiles. Reptiles are small, their skin is permeable, and their livers process these compounds slowly. This cause is easy to miss because the owner does not connect a spray used two rooms away with the animal.

Low blood sugar.

Seen in very small, very young, or severely debilitated lizards, and in animals with liver disease. It follows a period of not eating.

Organ failure.

Kidney and liver disease both produce neurological signs when waste products accumulate. Gout, which is the deposition of uric acid crystals in tissues, sits alongside renal disease in reptiles and is common in dehydrated animals and in herbivorous species fed too much protein.

Infection.

Bacterial, viral and fungal infections of the nervous system. Adenovirus in young bearded dragons is a recognised cause of neurological signs and wasting, and it often appears in a group of animals from the same source.

Nutritional deficiencies other than calcium.

Thiamine deficiency occurs in species fed largely on frozen fish, because some fish contain an enzyme that destroys thiamine, and it produces neurological signs. Vitamin E and selenium imbalances have also been implicated.

Head injury.

After a fall, an escape, or being dropped. Reptiles fall from height in the home more often than owners admit, and a bang to the head can produce seizures days later.

Dehydration and electrolyte disturbance.

Frequently the final common path in a lizard that has been unwell for a while.

What looks like a seizure and is not

Shedding.

Lizards twitch, jerk, rub and behave oddly during a shed. The animal remains aware, responds to you, and can right itself.

A cold lizard.

A reptile below its preferred temperature range becomes slow, unresponsive and floppy. That is torpor, not a seizure, and the treatment is to correct the heat gradually rather than to rush to an emergency vet in a cold car. It matters because the two look similar to a frightened owner and the responses are opposite.

Normal display behaviour.

Head bobbing, arm waving, dewlap extension and beard puffing are all coordinated, purposeful, and stop when the animal chooses.

Post-feeding behaviour.

Some lizards gape, hiccup or make odd movements after a large meal.

Muscle twitching from fear.

A lizard that has just been caught may tremble briefly and then settle.

The distinguishing question is always the same: is the animal aware, coordinated, and able to right itself. If yes, it is behaviour. If no, it is neurological.

During the episode

Do not pick the lizard up.

Restraint does not stop a seizure and it causes injuries. A lizard with metabolic bone disease has fragile bones and a fragile jaw, and both fracture easily during a struggle. Let the animal move; make the space safe instead.

Switch off the basking lamp and any ceramic heater.

A seizing lizard can press itself against a hot lamp or a heat rock and cause a deep burn without being able to move away. Turning the heat source off for a few minutes is safe; a burn is not.

Remove hazards rather than the lizard.

Take out the water bowl if it is deep enough for a face to end up in it. Take out branches and rocks it could fall from or knock into. If the enclosure has an open front, block it.

Never put anything in the mouth.

There is no risk of a reptile swallowing its tongue, and forcing something between the jaws breaks teeth, damages the jaw and gets you bitten. Reptile bites are contaminated and slow to heal.

Dim the room and reduce noise.

Sensory input can prolong or retrigger activity. Turn the lights down and keep people and other pets out.

Time it, and film it.

Note the time it started and stopped. Film the whole thing if you can, including the recovery. Vets rarely see the episode, and a thirty-second video answers questions that ten minutes of description cannot.

Immediately after

Move the lizard into a clean plastic container lined with paper towel. No substrate, no branches, no rocks, nothing to climb or fall from, and a secure lid with ventilation.

Put the container where it can reach a gentle warm end at the lower part of the animal's normal range, unless overheating is suspected, in which case move it somewhere cool and let the temperature come down.

Measure the enclosure temperatures now, at the basking surface, at the cool end and at the point the animal was sitting. Do it before anyone adjusts anything. If a thermostat has failed, that reading is the diagnosis.

Do not offer food or water yet. A disorientated animal aspirates.

Do not give calcium powder, liquid calcium, vitamin drops or anything else. Calcium given the wrong way, or given to an animal whose problem is not calcium, causes its own emergency. If you have an existing prescription for this animal, phone and ask before using it.

Call an exotics vet even if the lizard now looks normal.

A calm oral check belongs at the vet, not during an episode. A pale, tacky or bruised mouth and a soft jaw are things the vet will look for.

What the vet will want

Bring the video. It is the most valuable single item.

Bring measured temperatures: basking surface, cool end, overnight low, and the room. Say whether they were taken with a probe or an infrared thermometer.

Bring the ultraviolet details: lamp brand and type, wattage, distance from the animal, whether mesh or glass sits between, and the date it was installed. Ultraviolet output falls long before the lamp stops producing visible light, so a bulb that looks fine may be doing nothing.

Bring the diet in detail: which insects or plants, how the insects are gut loaded, which supplement products are used, how often, and whether they contain D3.

Bring a list of everything sprayed, plugged in, diffused, painted or used on another animal in the house in the past month.

Bring the weight now and a previous weight if you have one, the age, the sex if known, the species, and dates of the last shed, last meal and last droppings.

Expect blood tests looking at calcium, phosphorus, glucose and uric acid, and radiographs to assess bone density, look for fractures, and check for eggs or impaction. In a young bearded dragon with several affected animals from one source, expect questions about where it came from.

Preventing the next one

Fit a thermostat, and a second independent safety cut-out or a high-temperature alarm if the setup allows. Thermostat failure is a common and entirely preventable emergency.

Guard every heat source so the animal cannot touch it. Heat rocks in particular are a recurring cause of burns.

Replace ultraviolet lamps on the schedule the manufacturer specifies rather than when they stop lighting, and check the distance and whether mesh is reducing the output.

Dust and gut load feeder insects properly, using the supplement schedule your vet recommends for that species and life stage rather than a generic one.

Keep every aerosol, insecticide, diffuser and strong cleaner out of the room, and never treat another pet for fleas in the same room.

Keep water available in the form the species actually drinks from, whether that is a bowl, a dripper or misting.

Weigh the animal weekly and write it down.

When to get help

Go immediately for more than one episode in a day, an episode lasting more than a few minutes, a lizard that does not recover normal posture between episodes, or any seizure that followed a spray, a diffuser or a flea treatment in the house.

Go the same day for any single seizure, for fine twitching of the toes or jaw, for a soft or rubbery lower jaw, for a lizard that cannot lift its body off the ground, and for star-gazing or an inability to right itself.

Book an appointment promptly for a lizard that has had a fall or an escape and is now behaving oddly, even days later.

Recovery means an alert lizard that rights itself, moves in a coordinated way, basks at the correct temperature and starts eating again.