Egg-binding is a serious and sometimes fatal condition that affects female birds of breeding age. It can affect any bird, but among common pet birds, it is most often seen in smaller species including finches, parakeets, lovebirds, canaries, and cockatiels.
Basically, egg-binding means that the egg has become "stuck," and the bird is unable to expel it from its body within a normal time frame, which depending on species, can be anywhere from 24 to 48 hours. This causes the bird to strain in an attempt to pass the egg, which owners sometimes mistake as the bird straining to defecate. Your bird will likely appear ill, lose its appetite, fluff up its feathers, sleep more than normal, and may have a swollen abdomen. The stuck egg may make it difficult for your bird to pass feces and urine, as well.
Since it's so important for egg-bound hens to receive prompt medical treatment, owners should know what signs and symptoms to watch for in their pets. If left untreated, your bird can become critically ill and may die.
What Is Egg-Binding?
Many bird owners are surprised to learn that a female bird that has no contact with a male can still lay eggs. These eggs are not fertilized, so can not produce a viable chick, however. While not every pet female bird will lay eggs, the possibility is there for all of them.
Egg-binding occurs when an egg takes longer than usual to pass out of the reproductive tract. While the normal length of time to pass an egg varies between bird species, and even between individual birds, most birds pass an egg within 24 to 48 hours. Your bird might lay just one egg, or several eggs. It is possible for a bird to lay an egg normally, but then experience egg-binding with subsequent eggs.
The egg can become stuck inside the bird's vent, which is the opening for expelling materials from the urinary, gastrointestinal, and reproductive tracts. In this case, you might actually see a bit of the egg bulging through the vent.
Eggs can also bind higher up the reproductive tract. An egg may become stuck in the oviduct, which is the tube that leads from the ovaries to the vent, or within the cloaca, which is a chamber just within the vent that collects materials from the urinary, gastrointestinal, and reproductive tracts. Unlike mammals, birds have just one common opening/exit for these three organ systems.
Symptoms of Egg-Binding in Birds
Birds can hide symptoms of illness until the condition becomes too advanced to hide any longer. This helps wild birds survive, as a weak bird is an easy target for a predator but can make it difficult for a pet owner to realize their bird is ill. Recognizing the signs of egg-binding early on is key to your pet's survival. If you observe any of the following symptoms, contact an avian veterinarian as soon as possible. The vet can properly diagnose your pet's problem and get it on the road to a fast recovery.
Rapid or Labored Breathing
Many egg-bound hens look like they are having a hard time breathing, particularly after exertion, such as flying or fluttering within their cage. Even slightly labored breathing is a symptom of egg-binding.
An egg-bound hen may appear to have a swollen abdomen or show swelling around its vent from straining to pass an egg. Birds with swelling on any part of their bodies should be seen by a medical professional as soon as possible.
If you suspect that a hen may be egg-bound, watch its droppings. You should assume there's a problem if they look abnormal or if it fails to produce any at all.
One of the most common symptoms of illness in birds, fluffed-up feathers can also be a sign that a bird is egg-bound. If you observe your bird sitting with its feathers fluffed up, assess it for any other symptoms or abnormalities.
Egg-bound hens often visibly strain to try and pass their eggs. Egg-binding should be suspected in birds that strain but show no progress in moving their eggs.
Sitting on the Cage Floor
Most of the time, birds that are egg-bound tend to sit on the cage floor. Eggs that are stuck inside of a hen can put immense pressure on the bird's spine, sometimes causing paralysis and the inability to perch.
If the stuck egg puts pressure internally on the nerves that go into the bird's legs, it can cause lameness or even an inability to stand.
Loss of Appetite
This is a common symptom of several illnesses, but if you notice your bird is not eating, assess it for other signs of egg-binding.
Unfortunately, in some cases, the first and only sign that a bird is suffering from egg-binding is the sudden death of the bird.
Causes of Egg-Binding
There are several causes of egg-binding. The most common have to do with the egg itself, the bird's diet, or issues with the hen's reproductive tract.
Sometimes, the egg itself is too large for the hen to pass easily, or is positioned incorrectly inside the reproductive system, making it impossible for the bird to lay the egg normally.
Dietary issues are a common cause of egg-binding, particularly with birds that are deficient in calcium. Lack of calcium can cause eggshells that are weak or partially formed, and more prone to becoming stuck. Also, calcium, vitamin E, and vitamin D help the uterine and oviduct muscles contract forcefully enough to move the egg through and out of the hen's reproductive system. Obese birds are also at higher risk of egg-binding.
Infections, tumors, or inflammation within the hen's reproductive system can cause swelling that leads to egg-binding.
Diagnosing Egg-Binding in Birds
Often, your avian veterinarian can diagnose egg-binding just by gently feeling the hen's abdomen, as it is often possible to feel the stuck egg inside. However, most vets will take x-rays of the bird, which allows them to see the exact size and position of the stuck egg. Occasionally, an egg becomes stuck before the shell is fully formed, making it difficult to see on an x-ray. If your vet suspects this is the case, they might choose to do an ultrasound, which will show even a shell-less egg.
A bird suffering from egg-binding should be seen by a veterinarian right away, as the longer you wait, the less likely the bird is to survive. Once at the vet's office, if the bird is determined to be critically ill, it will be treated for shock. This usually includes warming the bird, giving fluids and calcium via an IV into a vein, and sometimes providing supplemental oxygen. In some cases, these measures are enough to allow the bird to pass the egg on its own.
If the egg doesn't pass, the veterinarian will assess its position inside the hen. If the egg is inside the cloaca, it sometimes can be massaged out or extracted with lubricated cotton swabs.
If the massage and natural methods don't extract the egg, it may be necessary to break the egg while it is still within the hen and remove it in parts. If this occurs, the vet will use a needle to remove the contents of the egg, which will cause the egg to collapse. The vet will then clean the hen's oviduct to remove any shell fragments or egg residue. Leaving anything in the hen could lead to infection or internal tissue damage.
With prompt treatment, most birds will survive. However, if the stuck egg causes the hen to be unable to easily breathe or expel waste, and the bird isn't provided emergency treatment, the prognosis is poorer.
How to Prevent Egg-Binding
Since egg-binding is a common condition, it is hard to completely prevent it. It's best to maintain a healthy lifestyle for your hen. Feeding a well-balanced diet that includes enough calcium is crucial, as is preventing your bird from becoming overweight. Your bird should have opportunities for exercise and play each day.
However, birds that tend to lay eggs frequently and have experienced egg-binding may be prone to more episodes of this serious condition. In that case, your vet might recommend hormone injections at the beginning of egg-laying season to prevent your bird from laying an egg.
Keeping daily watch on your hens will help you know their habits and be better aware if they are displaying any symptoms of egg-binding.