Hypocalcaemia in Birds: Seizures, Diet and UVB

Quick answer

A parrot found dazed on the floor of its cage in the morning has not simply fallen off its perch. One of the commonest reasons for that picture is a seizure, and one of the commonest reasons for a seizure in a pet parrot is low blood calcium.

A bird that grips confidently, holds itself square on the perch and moves without hesitation is showing you good neuromuscular function. Weakness and clenched toes are the early departures from this.

African grey parrots are affected far more often than other species, for reasons that appear to be specific to how they handle calcium. The background is nearly always the same: a diet based on seed, and a life spent entirely indoors behind glass, which means no ultraviolet light and therefore no vitamin D3.

• Calcium does not just build bone. It runs nerve conduction and muscle contraction, which is why the failure shows up as tremors, weakness and seizures rather than as a limp.
• Seed mixes, especially sunflower and peanut, are low in calcium and high in phosphorus and fat. A bird eating them exclusively is being slowly decalcified.
• Birds make vitamin D3 in the skin using ultraviolet B light. Ordinary window glass blocks UVB, so a bird sitting in a sunny window is getting warmth and light and no vitamin D at all.
• Seizures in birds have many causes, and several of them, particularly heavy metal poisoning, are emergencies with completely different treatments. Never assume calcium.
• Do not give calcium or any supplement by mouth to a bird that is seizuring or dazed. Get it to an avian vet.

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A bird that is seizuring, twitching, unable to perch, or found collapsed on the cage floor is an emergency. Go to an avian veterinarian immediately.

During the seizure itself, do not handle the bird, do not try to restrain it, and do not put anything in its mouth or beak. Turn the lights down, keep the room quiet, and clear away anything it could injure itself on.

Afterwards, move the perches down low or take them out, pad the cage floor with towels, remove hanging toys and swings, keep the bird warm, and travel. Birds are disoriented for a period after a seizure and fall repeatedly, and a fall from a high perch onto a hard base causes fractures and head injuries on top of the original problem.
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Decide in 60 seconds

Why calcium failure shows up as a seizure

Calcium is a signalling ion before it is a building material.

Most people think of calcium as bone, and bone is where the body stores it. But the fraction circulating in the blood is doing something quite different: it controls how readily nerve cells fire and how muscle fibres contract, and it is required for blood to clot.

When the ionised calcium in the blood falls, nerve membranes become unstable and fire too easily. Muscles twitch. Then whole groups of neurons discharge together, and that is a seizure.

This is why the presentation is neurological rather than skeletal, and it is why the condition is so easily mistaken for epilepsy, a stroke or a night fright.

Three things have to work, and a pet bird often has none of them.

Calcium has to be in the food. Vitamin D3 has to be present to absorb it from the gut. Parathyroid hormone has to regulate the balance between blood and bone.

A parrot on a sunflower and peanut mix has very little calcium in the diet and a large amount of phosphorus, which actively works against it. A parrot living indoors behind glass makes no vitamin D3. The parathyroid glands respond to the resulting shortfall the only way they can, by dissolving the bird's own skeleton to keep blood levels up.

Why African greys in particular.

African grey parrots are strongly over-represented in cases of hypocalcaemic seizures, and they often present acutely without the obvious skeletal thinning seen in other species. The working explanation is that they are less able to draw on bone stores when blood calcium falls, so instead of a slow decline they hit a threshold and fit.

What this means practically is that an African grey can look completely well, eat, talk, play and preen normally, and then have a seizure with no warning. In this species, prevention is not optional and waiting for symptoms is not a plan.

Why it gets missed

The seizure is not seen.

Most happen when nobody is in the room, or at night. The owner finds a bird on the cage floor, assumes it slipped, puts it back on the perch, and it recovers over an hour. This can happen several times before anyone considers a seizure.

It is blamed on a night fright.

Thrashing in the dark is common in some species, particularly cockatiels, so a bird found disoriented in the morning gets a plausible innocent explanation.

Seed mixes look like food.

They are marketed as complete, birds love them, and a bird eating enthusiastically does not look like a bird with a nutritional deficiency. Seed diets fail slowly and invisibly.

The window looks like sunshine.

A cage in a bright window feels like the right thing to do, and in every respect except the one that matters here it is. UVB does not pass through glass, so that bird has had none for its entire life.

The bird hides everything else.

Birds conceal illness until they cannot. A parrot showing weakness has often been compensating for a long time.

What healthy looks like

Perch height and cage layout become a safety decision the moment a bird has had a seizure. Low, wide perches over a padded base prevent the injuries that follow the fit.

Grips the perch firmly with toes wrapped and no trembling.

Moves confidently around the cage, climbs, hangs, and lands accurately when flying.

Stands square and even, with no wing droop and no shifting of weight.

Eats a varied diet that includes formulated food and fresh vegetables rather than seed alone.

Holds a steady weight on a weekly gram scale.

Feathers smooth, well formed and evenly coloured, with no black or abnormal bars across new feathers.

A hen that lays occasionally rather than repeatedly, and produces normal, firm-shelled eggs when she does.

Fixing the diet

This is the part that actually prevents recurrence, and it is slower and more delicate than it sounds.

Move from seed to a formulated diet.

A good quality pelleted or extruded food designed for the species is the foundation, because every mouthful has the same balanced composition and the bird cannot pick out the fatty bits.

Convert gradually and weigh every day.

This matters enormously. Birds do not recognise unfamiliar objects as food, and a parrot will genuinely starve beside a bowl of pellets it does not believe in. Never remove seed abruptly and hope hunger solves it.

Work with an avian vet on a conversion plan, offer the new food at the times the bird is most motivated, model eating it, mix and shift the ratio slowly, and weigh the bird on a gram scale every single day during the transition. Any meaningful weight loss means stop and reassess.

Add calcium-rich fresh foods.

Dark leafy greens such as kale, spring greens, bok choy, dandelion and broccoli, plus cooked pulses and other vegetables appropriate to the species. Keep the variety wide.

Spinach and chard are high in oxalate, which binds calcium and reduces how much the bird can absorb, so they are poor choices as the calcium source even though the tables say they contain plenty.

Cut the high-fat seeds right back.

Sunflower seed, peanuts and similar items become occasional training treats rather than the diet.

Cuttlebone and mineral blocks are a supplement, not a plan.

Some birds use them, many ignore them, and you cannot measure what was taken. Provide one, but never count it as the calcium supply.

Do not add calcium or vitamin D3 supplements on your own initiative.

Calcium given without adequate vitamin D3 is poorly absorbed. Vitamin D3 given in excess causes calcium to precipitate in the kidneys and other soft tissues, which is its own serious disease. Both belong on a vet's prescription, at a dose set for your bird.

Getting ultraviolet light right

Window sunlight does not count.

Glass blocks the UVB wavelengths that drive vitamin D3 synthesis. So do most plastics and most fine mesh. A bird sunbathing indoors gets heat, light and pleasure, and no vitamin D.

Real outdoor time is the best source.

Time in a secure outdoor aviary or a safe, escape-proof carrier outdoors, with shade always available so the bird can move out of the sun, is the most natural provision. It has to be genuinely secure, because an escaped parrot is usually a lost parrot, and it needs protection from cats, birds of prey and overheating.

Otherwise use a proper avian UVB lamp.

Buy a lamp made for birds or reptiles that emits UVB, not a bulb sold as full spectrum or daylight for its colour rendering, which is a different thing entirely.

Mount it at the distance the manufacturer specifies, since output falls off sharply with distance, and make sure part of the cage is out of its beam so the bird can choose.

Run it on a timer for a defined daily period rather than continuously.

Replace it on schedule. UVB output decays long before the lamp stops producing visible light, so a bulb that still looks fine may be doing nothing.

Do not place it too close or leave a bird unable to move away, because excessive ultraviolet exposure damages eyes and skin.

Sleep still matters.

UV provision does not replace a long, dark, uninterrupted night. Light cycles also drive hormonal behaviour, and a hen kept under long day lengths is more likely to lay repeatedly and to deplete her calcium.

The routine that prevents it

Watch how the bird stands and grips during a daily look-over. Weakness, tremor and a dropped wing appear here before anything dramatic happens.

What never to do

Do not restrain or hold a bird that is actively seizuring.

Do not put anything into the beak of a seizuring or dazed bird. Birds aspirate easily and it is often fatal.

Do not give calcium supplements, vitamin D3, or any human product to a bird without veterinary direction.

Do not leave perches high, or hanging toys and swings in place, after a seizure.

Do not decide it was a night fright and move on, especially in an African grey.

Do not switch a seed-addicted bird straight onto pellets and leave it to get hungry.

Do not treat a sunny window as ultraviolet provision.

Do not keep a UVB lamp running past its replacement date because it still lights up.

Do not let a hen lay clutch after clutch without veterinary involvement.

Do not assume a bird that recovered within an hour is fine. Repeat seizures get worse, and the underlying deficiency is still there.

When to get help

Recovery looks like a bird that perches steadily again, grips without trembling, eats a varied diet and holds its weight week to week.

Go to an avian veterinarian immediately, including out of hours, for any seizure, tremor, twitching, weakness, inability to perch, or a bird found collapsed on the cage floor. Lower the perches and pad the cage before you travel.

Go the same day for a wing droop, curled or clenched toes, repeated falls, a hen straining or laying soft-shelled eggs, or a young bird with bent limbs or a fracture from a minor knock.

Book a wellness appointment, without waiting for symptoms, for any bird on a seed-based diet, any bird that has never had ultraviolet exposure, and any African grey of any age, and ask specifically about ionised calcium.

Bring the exact diet including brand names and what the bird actually eats rather than what is offered, your weight log, the light and sleep schedule, whether the bird has ever had UVB and from what source and when the lamp was last changed, a full list of anything it chews including cage metal and household items, the laying history for a hen, and a phone video of the episode if anyone saw it. That video is often the single most useful item you can bring.