Egg binding in chickens

An eggshell forms inside a hen with the pointed end facing the vent. As the egg moves toward the cloaca, it turns end for end, so the large end comes out first.

What is egg binding?

Sometimes an egg gets stuck before it is laid, in which case the hen suffers from oviduct impact. In common terminology, the hen is suffering from egg binding. 

Egg binding causes

Egg binding has many different causes. Here are some of them:

• Obese hen — Pet hens pampered with too many fattening treats are susceptible to egg binding. Extra body fat puts pressure on the muscles responsible for pushing the egg out, preventing the muscles from doing their job.
• Unusually large egg — The egg may be too large, such as one with multiple yolks. Or a pullet has started laying at too young an age, and therefore produces eggs that are larger than her undeveloped muscles can handle.
• Cold weather — Extremely cold weather can stiffen a hen’s egg-laying muscles. Stiff muscles can’t properly contract to push the egg out.
• Calcium deficiency — Calcium, needed for muscle contractions, may be deficient in the hen’s diet. The best layers are especially prone to depleted calcium reserves if their bodies can’t replace used-up calcium fast enough to keep up with egg production.
• Age — Older hens are also susceptible to calcium depletion. One reason backyard chickens seem to egg bind more often than in the past is that they live longer as beloved family pets.
• Disease — Sometimes a disease causes the oviduct to swell or the hen’s muscles to lose tone.

Signs of an egg-bound hen

An egg-bound hen will appear sluggish. She may strain, as if trying to poop or lay an egg, and she may waddle like a penguin. She may frequently enter the nest box and exit without laying. Her vent will swell, and her abdomen will bloat and feel hard to the touch.

You know egg binding is the cause if you can see the egg protruding from the vent when the hen strains to release it. If the egg is not visible, lubricate a finger with K-Y Jelly or other water-based lubricant and gently insert it into the vent until the end of your finger touches the hard shell, no more than 2 inches in. If you don’t feel an egg, seek some other cause for the hen’s behavior, as she is not egg bound.

When a hen becomes egg bound, more eggs accumulate behind the stuck egg, which causes the hen’s abdomen to distend. Plus, the stuck egg blocks the hen’s ability to poop. Unless you can get things moving, the hen will go into shock and die.

A veterinarian can verify egg binding by taking an x-ray. A vet who ascertains the hen is indeed egg bound can begin immediate treatment.

How to remove a bound egg in chickens

Often simply applying moist heat will relax the muscles enough to release the stuck egg. You can provide moist heat by applying a warm, damp towel to the hen’s bottom.

Moisten an old towel, warm it in the microwave (make sure it’s not hot enough to burn) and hold it against the hen’s vent. Reheat the towel as needed to keep it warm or use two towels and warm them alternately.

Another method of applying moist heat is to stand the hen in a basin with enough warm water to reach just above her vent. If moist heat doesn’t release the egg after about 15 minutes, let the hen rest for 15 or 20 minutes and try again.

Failing that, put on a disposable glove and lubricate the vent and egg with K-Y Jelly and/or gently squirt in warm (not hot) saline-solution wound wash or soapy water. Sometimes at this point the egg will emerge on its own.

Otherwise, lubricate your gloved index finger. Then gently insert your finger until you feel the egg. Try to maneuver the egg while, with your other hand, pushing gently against the hen’s abdomen to work the egg out.

Do not attempt to stretch the vent, which could tear delicate tissue. And be careful not to break the egg, which can cause internal injury.

Advanced treatment 

If all else fails, you will need to collapse the shell to remove the egg. This maneuver is tricky. Unless you work slowly and carefully, the broken shell could seriously injure the hen, resulting in infection and death.

But if the egg doesn’t come out, the hen won’t make it anyway. You may, at this point, prefer to seek the help of a veterinarian.

To remove the egg yourself, first suck out the contents by piercing the shell with a syringe and large-bore needle, 18 gauge or lower. Once the shell is empty, collapse it while trying to keep the pieces together. This part is the trickiest since you must take great care to avoid injuring the hen.

To avoid injury, do not squeeze the abdomen to crush the egg. Rather, work gently with your fingers directly on the shell, or with one or two fingers on the inside and the other hand gently pressing from the outside.

With the aid of lots of warm saline or soapy water as a lubricant, carefully remove as much of the shell as possible. Then rinse away the remaining pieces. A turkey baster comes in handy for this.

Squirt gently enough not to wash the shell bits deeper. Don’t worry about getting the last tiny bits. Once the egg is out, the hen is better off left to rest, and any bits left behind should come out on their own.

If, at this point, tissue protrudes outside the vent, clean the tissue, apply an anti-inflammatory cream (such as hydrocortisone), and gently push the tissue back inside the hen. Repeat as needed.

Isolate the hen until the protruding tissue retreats inside. Otherwise, the pink tissue will attract flock members to pick at it.

Tips to avoid egg binding

Once the stuck egg is released, egg binding may recur if the underlying condition is not corrected. Egg binding is less likely to happen in the first place when hens are fed a balanced diet.

Pullets should not be fed a layer ration until they start laying eggs. Laying hens should eat mainly formulated layer ration supplemented with free-choice oyster shell or other calcium supplement. And keep high calorie treats to a minimum.

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