Egg Binding

In this episode of Current Vet, Dr. Lottie talks about egg binding (avian dystocia) in chickens and pet birds, why it can become serious so quickly, the key clinical signs to recognise and how to stabilise and treat these birds when they present.

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Timeline:
00:00 Intro
00:42 Case
02:31 Aetiology & Pathogenesis
09:26 Clinical Signs
11:14 Diagnosis
15:39 Treatment
23:17 Prevention
24:35 Key Points
26:25 Outro

References

• Abou-Zahr, T. (2022) ‘Avian reproductive disorders’, Companion Animal, 27(2). Available at: https://doi.org/10.12968/coan.2021.0056.
• Clayton, L.A. and Ritzman, T.K. (2006) ‘Egg Binding in a Cockatiel (Nymphicus hollandicus)’, Veterinary Clinics: Exotic Animal Practice, 9(3), pp. 511–518. Available at: https://doi.org/10.1016/j.cvex.2006.05.004.
• Harcourt-Brown, N.H. (1996) ‘Torsion and Displacement of the Oviduct as a Cause of Egg-Binding in Four Psittacine Birds’, Journal of Avian Medicine and Surgery, 10(4), pp. 262–267. Available at: https://www.jstor.org/stable/30134507 (Accessed: 8 September 2026).
• Vavlas, A. et al. (2025) ‘Resolution of egg binding is possible in most client-owned parrots when multiple treatment strategies are considered’. Available at: https://doi.org/10.2460/javma.24.11.0749.
• Jenkins, J.R. (2000) ‘Surgery of the Avian Reproductive and Gastrointestinal Systems’, Veterinary Clinics of North America: Exotic Animal Practice, 3(3), pp. 673–692. Available at: https://doi.org/10.1016/S1094-9194(17)30069-5.
• Abou-Zahr, T. et al. (2019) ‘Percloacal Ovocentesis in the Treatment of Avian Egg Binding: Review of 20 Cases’, Journal of Avian Medicine and Surgery, 33(3), pp. 251–257. Available at: https://doi.org/10.1647/2018-376.

Current Vet is an educational podcast intended for veterinary students, veterinary professionals, and individuals with an interest in veterinary medicine.

All content provided in this podcast and its associated materials is for educational and informational purposes only. It is not intended as, and must not be considered a substitute for, professional veterinary advice, diagnosis, or treatment.

Any clinical cases discussed in this podcast are fictional, and are designed to reflect typical or likely clinical scenarios for educational purposes. They do not represent specific real-life cases, clients, or animals.

While every effort is made to ensure accuracy and alignment with current evidence at the time of publication, veterinary medicine is a rapidly evolving field, and recommendations may change over time.

Creators and Guests

Host

Dr. Lottie Wilkinson

Creator and host of the Current Vet podcast

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Egg Binding- Veterinary Vista
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[00:00:00] Hello, hello, and welcome back to Current Vet, the podcast that makes veterinary medicine simple. I'm your host, Dr. Lottie, and today we're talking about egg binding in birds, also known as avian dystocia. So it's a very common problem in any bird species, but especially in our laying hens and also our companion psitacines as well, and it can become quite a serious problem quite quickly.

It can also be confused with some GI problems, maybe neurological weakness, or just nonspecific illness as well if the bird is sitting maybe just fluffed up in the corner and showing vague signs. So let's get straight into a case.

A two-year-old backyard chicken called Mabel is presented to your clinic.

She lives in a small flock of five hens, and these girls are considered part of the family to the owners. Her owner tells you that she's normally the first one to run over for food in the morning, but this morning she just stayed in the [00:01:00] coop. She's been much quieter than usual for the last 12 hours. She is still standing, but she looks quite hunched and fluffed up.

Her owner noticed that she's been visiting the nest box repeatedly, but no eggs have been noticed yet. There's been no obvious trauma, no predator attacks, no recent changes in the flock, and the owner makes sure to keep the coop really nice and clean. They feed a nice commercial layer pellet and offer oyster shell as well.

On exam, Mabel is quiet but responsive. She's slightly tachypnoeic, her feathers are fluffed, and her celom feels a little bit distended caudally. There's some soiling around the vent, but no obvious prolapsed tissue. You palpate carefully and feel a firm, rounded structure in the caudal celom, which does feel like an egg.

So at this point, egg binding is gonna be probably at the top of your differential list. But a couple of other differentials to consider for a hen that is quiet, hunched, straining, or has [00:02:00] that distended celom are going to include egg peritonitis or egg celomitis, salpingitis, oviduct or GI impaction, or a salomic mass or neoplasia.

But that combination of the recent repeated nest box visits, the straining, failure to lay, and then the caudal celom distension and palpation of a firm egg-like structure is all gonna make egg binding very likely.

So what actually is egg binding? This just means that the bird is unable to pass an egg normally through the reproductive tract. The more kind of medical term is dystocia. And a bit more specifically, dystocia means difficult or obstructed egg laying, but they are essentially the same and often used interchangeably.

So in chickens, the egg is usually stuck in the distal oviduct, the shell gland, the vagina, or near the cloaca. Okay, [00:03:00] so to understand egg binding, we need to understand what normal egg laying looks like. So in female birds, the ovary produces the yolk. The yolk enters the oviduct where parts of the egg are added to it as it moves along through the oviduct.

So the oviduct is gonna add the albumen, which is that egg white, the clear part around the yolk. They're gonna add the shell membranes and then finally the shell. The egg then passes through the vagina and the cloaca and is laid. So for that to happen normally, the bird is going to need a fully functional reproductive tract, good muscular contractions throughout the oviduct to pass the egg through, adequate calcium levels, good hydration, enough energy reserves, a normally shaped and formed egg, no obstructions throughout the oviduct or around the cloaca or vent, and then enough strength and energy to complete this whole process.

Calcium is really important for two main [00:04:00] reasons. So first of all, it's needed to form the shell of the egg, and secondly, calcium is also needed for good smooth muscle contraction. So a calcium deficient bird can have both abnormal shell formation and weaker contractions, both of which are gonna put them at a much higher risk of dystocia. But why does egg binding actually happen?

So there are so many different reasons why it could happen. It is not a disease with one single cause. So the egg can fail to pass because of problems with the bird, problems with the egg, or problems with the reproductive tract. So we're gonna talk through a couple of top risk factors for each of these three categories.

Bird related risk factors are gonna include hypocalcemia, vitamin D deficiencies, poor muscle tone, obesity, being dehydrated or systemically ill, being physically exhausted, being quite young age, older age in some birds as they're getting [00:05:00] weaker and more tired and they're not producing eggs as normally, and then also chronic egg laying.

So in pet birds, chronic egg laying is a major risk factor, and that repeated egg production can hugely deplete calcium reserves and then cause ongoing metabolic stress as well. A couple of egg related risk factors are gonna include oversized or double-yolked eggs, misshapen eggs, soft, rough, or thinly shelled eggs, if they are broken within the oviduct, and then eggs that get stuck in an abnormal position.

Those large and misshapen eggs can physically struggle to pass through the oviduct, but the soft-shelled eggs are also a problem because it does not give the oviduct that same firm structure for it to push against. So instead of moving as a solid object, the egg is going to deform, fold, or collapse, which then makes movement through the oviduct much more difficult.

Some reproductive tract [00:06:00] factors are going to include inflammation or infection, so like salpingitis. We could have impaction or torsion within the oviduct. We might have strictures or adhesions, neoplasia and other masses causing obstruction within the tract, previous trauma, cloacal disease, or vent trauma, especially from things like pecking.

So this is really important because while the stuck egg may be the clinical presentation, there may be underlying conditions that have led to that occurring which are also gonna need to be addressed to make sure that further episodes are prevented as well.

There are a couple of environmental factors that can contribute as well. So these are gonna include lack of appropriate nesting areas, so hens aren't gonna want to go and nest or go and lay their egg if they don't have a place to do so. Ongoing stress, poor lighting patterns for the birds, inadequate diets for their species, [00:07:00] limited calcium intake, poor exercise, overcrowding, dehydration, and heat stress.

In Mabel's case, the owner is pretty hands-on and observant, and their setup sounds pretty good overall. But we do need to make sure that we're still asking about their diet, any treats they're getting, making sure that their diet includes enough calcium, shell quality in the flock, whether they're laying misshapen or strange eggs, their history of egg production, recent weather changes, their access to water, and then any changes in the pecking order that may be causing stress within the flock.

So what is happening inside Mabel? So the egg has moved through the oviduct, but for some reason it has become stuck. So once the egg is stuck, several things happen. The oviduct can continue to contract around it, which is gonna cause pain and [00:08:00] straining and muscular fatigue. The retained egg takes up space in the coelom, and birds don't have a diaphragm, and their respiratory system depends on the movement of the sternum and the body wall.

So anything that distends the coelom can cause respiratory compromise as it compresses the air sacs and restricts respiratory movements. A large egg or a distended reproductive tract can also compress nearby structures, so it may press on the GI tract, which is gonna cause reduced dropping or abnormal feces.

It can press on nerves and vessels in the pelvis leading to neurological weakness, lameness, or a wide-based stance. It can interfere with urination or defecation through the cloaca if that is being blocked. And if the egg remains stuck, the bird becomes increasingly exhausted, painful, dehydrated, and it can progress to systemic illness.

If the egg breaks internally or the [00:09:00] oviduct ruptures or tears, yolk and egg material can then enter the coelomic cavity resulting in really severe inflammation. We can then get secondary bacteria infection, severe coelomitis, possibly then sepsis and death. So even if the initial issue is just reproductive, the consequences can become systemic pretty quickly.

So what clinical signs may we see? Mabel is showing a pretty classic presentation. So top clinical signs of egg binding in birds are gonna include fairly non-specific signs like reduced activity, the fluffed up feathers, sitting quite low or hunched up, repeated visits to the nest box, straining, tail bobbing, that wide-based stance.

Maybe we might see lameness or weakness if we've got compression of nerves, reduced appetite, abnormal droppings. We may [00:10:00] see stomach distension, that increased respiratory effort if they're not able to breathe as normal. Cloacal swelling, vent soiling, and then also cloacal prolapse can occur if they are just chronically straining.

In small pet birds, the signs may be a little bit more subtle, and they can progress quite rapidly. So a budgie or cockatiel may be sitting at the bottom of the cage just looking quite fluffed up, weak, and then breathing with increased effort. So that tail bobbing is gonna be a sign of respiratory distress.

In chickens, owners may notice the hen spending more time in the nest box. They may be straining, waddling a bit, standing in that wide-based stance, or just sitting separate from the rest of the flock and behaving abnormally. But one of the most important points in this to remember is that birds mask illness really, really well.

So by the time a bird is sitting, even with non-specific signs like that fluffed up, weak appearance, [00:11:00] it may already be that they are quite systemically ill. So egg binding should be treated as urgent, especially if we're seeing those systemic signs.

Diagnosis is often based on the history and physical exam. So the key areas to assess are going to be the body condition and muscle mass, making sure that they're not obese, predisposed to egg binding, their hydration status, respiratory effort, coelomic palpation, and then checking the vent and cloaca, any signs of prolapse, any discharge, or any evidence of trauma from things like vent pecking.

Coelomic palpation may reveal that firm egg shape structure, but we must not be squeezing really hard. If the egg is fragile, if it's cracked, if it's soft-shelled, if it's abnormal, aggressive palpation or firm palpation can cause it to rupture or [00:12:00] actually damage the oviduct. In some cases, the egg is actually quite distal in the reproductive tract, and it may be seen or felt from the cloaca. In other cases, it's a bit higher up the reproductive tract, and it can't be safely reached.

So once we've done a physical exam and we suspect egg binding based on the presentation and the history, we can then pursue some further diagnostics, especially if we're not certain what the diagnosis is or if the bird appears systemically quite unwell. We need to investigate potentially those underlying causes and make sure that there's not something underlying that has led to egg binding.

Imaging with radiographs is gonna be one of the most useful tests to do. This can help you assess how many eggs there are, the size, its position, whether it's likely to pass either on its own or with manual help. We can assess the shell. If it's a soft-shelled egg, [00:13:00] it may not be as visible on radiographs, but normally shelled eggs should appear well on radiographs.

We can assess whether it's normally shaped, whether the egg is likely to be too large to pass normally. Other causes of abdominal enlargement, other underlying causes of egg binding, like neoplasia or torsion. We may see any signs of skeletal disease or fractures. But remember that those soft-shelled eggs are often much harder to see radiographically.

You may only see like a faint outline or that abnormal soft tissue opacity structure, or we may just see coelomic distension. So a normal looking radiograph is not always going to completely rule out egg binding. But using ultrasound as a follow-up to radiography is gonna be really useful if we suspect a soft-shelled egg, if we're looking for some oviduct disease, so that's soft tissue opacity structures, coelomic masses, egg yolk coelomitis, or other fluids within the coelom.

[00:14:00] We can then do blood work to check the bird's systemic health and the likelihood of underlying conditions. So a couple of things we might wanna assess are gonna be things like packed cell volume, total solids to check for hydration status, things like calcium to make sure that they do have good calcium levels.

It is important to remember that a laying bird and a reproductively active female bird is often hypercalcemic, and this is pretty normal in laying birds. So a hypocalcemic bird is definitely a red flag if they are laying eggs, and actually even low to normal levels of calcium can be a red flag of a sign that they don't have sufficient calcium to be laying eggs.

We can then also check the glucose, uric acid levels if potentially we're suspecting blockage of urate excretion. We can check their electrolytes, white blood cell count, or other evidence of inflammation or infection [00:15:00] if we suspect secondary infections If the bird's stable and the clinician knows what they're doing, a careful cloacal exam can then be performed.

So this is gonna help determine whether the egg is close enough to the cloaca and to the vent to be manipulated or removed. But again, this is not something we're just gonna do straight off the bat, as the cloaca and oviduct are very delicate. The bird may be very painful, unstable, or quite stressed. So if we are doing this, it needs to be in suitable conditions with a stable bird and with good sedation on board so we're not causing undue stress or actually deterioration.

Once we know what we're looking at, treatment is then going to depend on four main things. So one is how stable the bird is. Two is where that bound egg is. Three is whether the egg is intact. And then four is whether there's any underlying conditions that need treating. So the options are gonna [00:16:00] range from supportive care and medical management, all the way through to the manual removal of the egg, ovocentesis, or surgery.

So let's talk a bit about stabilization first. For Mabel, the first step is definitely going to be supportive care, and this can actually often be sufficient to stimulate egg laying in some birds in some milder cases. But in cases that don't respond to just stabilization and medical management, we then may need further interventions.

But for stabilization, we're gonna provide a warm, quiet environment. Sick birds use a lot of energy trying to maintain their body temperature, so keeping them warm helps to reduce that energy demand and can improve their comfort. So this might mean hospitalizing her in a warm, quiet cage, in an incubator away from noise and predators.

But make sure that we avoid overheating, and make sure that she can move away from the heat if needed. If there are signs of respiratory [00:17:00] compromise, oxygen supplementation is obviously indicated. Birds with that coelomic distension may struggle to ventilate normally, and then handling and manipulation can make this worse.

So if Mabel was open-mouth breathing or tail bobbing, we would definitely be putting her in oxygen. Fluid therapy is important if the bird is dehydrated or systemically unwell, and these can be given subcutaneously, IV, or even intraosseously, depending on the bird's size and then the severity of disease.

Sub-cut fluids are gonna be appropriate for more mild to moderate dehydration, but critical birds may need that more intensive support. And then rehydration is gonna help because dehydration reduces tissue perfusion, worsens the weakness, and then can also make passage of the egg more difficult Egg binding is painful, so we must remember analgesia.

NSAIDs are often used, or opioids can also be [00:18:00] considered if the bird is particularly painful or in really severe cases. Calcium is a really important treatment to add. It's gonna support that smooth muscle contraction and helps the oviduct to pass the egg. It is especially important if we do suspect hypocalcemia or if the bird is a chronic layer, if we've had poor eggshell quality recently.

And we can give calcium IV in cases where that bird is struggling or particularly fatigued, but then we also have oral calcium supplements available to help prevent recurrence in the longer term. If the egg is very distal, lubrication of the cloaca can help just to ease its passage in that last little bit, and this is gonna be most useful if the egg is near the cloaca and the bird is stable. But it's not an excuse to start forcefully manipulating the egg and trying to force it out through the cloaca, as that can be dangerous.

Okay, so once Mabel is warm, she's [00:19:00] hydrated, she's got analgesia on board, and we've given some calcium, we're going to reassess. Like we said, in the early or mild cases, the supportive care and just giving her some time may allow her to pass the egg without further intervention.

But if not, we can consider some medical interventions. Things like arginine vasotocin or prostaglandins can be given to stimulate muscle contractions, but these should not be given willy-nilly in every case we see. So we don't wanna force the oviduct to strongly contract against an egg that is gonna be maybe too large to pass, maybe malpositioned, or adhered to the oviduct wall, or if there's underlying disease that is gonna increase the risk of rupture or trauma to the oviduct.

Contraction-simulating drugs are considered after calcium has been used, after stabilization has been done, and then ideally when we know that the egg is going to be able to pass by itself, [00:20:00] i.e., there is no obstruction, there is no trauma, and the egg is normally shaped and likely to be able to pass on its own.

If both of these approaches don't work and the egg is still close to the cloaca, the bird is stable, manual removal may be possible, but this must be really gentle, controlled, and performed with good analgesia or anesthesia, depending on the bird and the case. So the aim is to help the egg pass without damaging the oviduct or cloaca.

We're gonna make sure we lubricate the cloaca, gently massage from the outside of the bird, carefully guide the egg towards the vent, and then support it as it passes. If the egg doesn't move easily, you must stop and reassess because forceful manipulation can cause a lot of damage.

If the egg is intact but cannot pass, another option is [00:21:00] ovocentesis. So ovocentesis means aspirating the contents of the egg to collapse it, making it easier to remove. And this can be done through the cloaca if the egg is accessible or through the body wall in some cases, depending on the egg position and then obviously the clinician's skills. It's not ideal to do it through the body wall because this can introduce infection into the coelom, so doing it through the cloaca is much better option.

Basically, the idea is that the bird is stabilized, we locate the egg, use careful aseptic technique, aspirate the egg contents back into a syringe, collapse that shell, and then remove the shell fragments really carefully so they're not tearing the oviduct or causing trauma. But of course, those risks are gonna include oviduct damage or maybe rupture, leakage of the egg contents into the coelom causing coelomitis. We may have hemorrhage, we may have [00:22:00] infection, and then we can also have retained shell fragments if not all of them are taken out.

In the more severe cases that just aren't responding to any of these approaches, we may need surgery. So for example, if an egg or oviduct rupture is suspected, there has been no response to medical management, or they're suspecting underlying disease like an egg yolk coelomitis or impaction or obstruction, surgical options are gonna include removing the egg through the oviduct, a coeliotomy, or salpingohysterectomy.

So for Mabel, you start medical management. You make sure she's warm, she's hydrated, you give calcium, analgesia, and you lubricate the cloaca. After an hour or so, she does begin to strain again, and then with gentle assistance and lubrication, she does pass the egg. After she is quieter but much more comfortable, and you continue monitoring her for several hours, check that she's breathing comfortably, she's [00:23:00] able to stand, she's starting to eat, and she's passing droppings as normal.

Before discharge though, we need to make sure that we discuss the risk of recurrence and then making sure we're talking about preventative strategies with the owners as well.

So for backyard chickens, we need to be making sure we're discussing giving a complete commercial layer diet with a good calcium content. We're avoiding excessive treats and maintaining good body condition, ensuring they have constant access to fresh water. We're monitoring that eggshell quality and their laying patterns, encouraging normal exercise and movement, providing clean and safe nest boxes, reducing any stress in the flock, and then monitoring for recurrent episodes as well.

For pet birds like parrots and other psittacines, prevention can also include making sure they get that species appropriate diet, [00:24:00] calcium and vitamin D support, UVB or appropriate lighting, reducing chronic reproductive stimulation, so controlling that photoperiod, making sure the owners aren't stimulating reproductive activity through over-grooming them or interacting with them in a way that they interpret as mating. Avoiding excessive high fat seed diets, and then considering hormonal therapy, so like a Deslorelin implant in our chronic layers.

So if you remember nothing else from today's episode, make sure you remember these points. Egg binding means a bird is unable to pass an egg as normal. It can affect any bird species, including chickens, parrots, budgies, cockateels. You can have ducks, pigeons, and loads of other laying birds. Clinical signs are gonna include straining, repeatedly visiting the [00:25:00] nest or nest boxes, fluffed up feathers, weakness, inappetence, reduced or abnormal droppings, coelomic distension, and then respiratory effort as well.

Radiographs are very useful for identifying stuck eggs or assessing the egg size, number, and position, but then ultrasound is useful for looking at those softer-shelled eggs or identifying underlying conditions like coelomitis or masses or obstructions. Supportive care with fluids, providing that warm, safe environment, calcium supplementation, and lubrication may be all that's needed to allow that bird to pass the egg.

But manual removal, if attempted, must be gentle, as forceful pressure can cause the egg to rupture or we can damage the oviduct. Medical stimulation of muscle contraction can be considered, but only when we know that there are no [00:26:00] obstructions to the egg passing, and then ovocentesis or surgery may be needed if medical approaches fail and the egg just isn't passing, or there is an underlying disease as well.

Prevention is gonna depend a little bit on the species, but it includes making sure they're getting appropriate nutrition, calcium supplementation, maintaining a healthy body condition, and then providing a safe nesting environment. And that is egg binding. Thank you so much for listening to this episode of Current Vet.

If you found it helpful, follow or subscribe wherever you get your podcasts and share it with a friend or colleague who could use a refresher on this topic as well. As always, if there's a topic you would like covered in a future episode, let us know in the comments or come and find us on Instagram and TikTok @veterinaryvista.

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