raising happy, healthy chickens

Common Egg Shell Quality Problems

If you have chickens, it’s very likely that you’ve seen eggs with some egg shell quality problems. And that mostly affects big farms that sell to grocery chains, since people like uniformity. However, for backyard chicken owners, it’s not that big of a deal to have a weird egg, unless it’s caused by disease. So I’ll go over the most common egg shell quality problems, the causes, and how to rectify the issues.

This is the part where most people would go over egg development. But I am not going to do that, because, I figure, if you really wanted to know how an egg becomes this yummy, beautiful food we eat for breakfast (or other times of the day), then you can click here.

Common Factors Affecting Egg Shell Quality

There are at least 7 factors that influence the quality of egg shells and even eggs, including:

  • The hen’s age
Mixed Backyard Flock at Backdoor of House

The quality of egg shells deteriorates with age as does the laying habits of the bird. She’ll start to lay eggs less frequently. And sometimes the older certain hens get, the bigger their eggs will get.

  • The hen’s breed
group of hen inside cage
Photo by Artem Beliaikin on

Commercial, hybrid-hens have been bred many decades to come up with the perfect egg shape. This isn’t the case with our typical backyard birds, so sometimes they might come out looking funky.

  • Nutrition of the laying hen
Layer feed for chickens

Getting the perfect egg requires a high grade diet.

  • Quality of the birds’ water

Saline water severely and adversely affects the quality of eggs and egg shells.

  • Management of and lighting schedule

If your chickens are used for egg production, then whether you use artificial light, and if you use it correctly, are of utmost importance with egg shell quality.

  • Health problems and disease
person in green crew neck t shirt holding white chicken
Photo by cottonbro on

Heat stress, vitamin deficiencies, and respiratory illnesses will all cause egg shell quality problems.

  • And stress

I mentioned in another post how stress, like over crowding, bullying, and predators can affect the laying habits of birds. I knew that it would cause chickens to stop laying, but I didn’t know that it would cause egg shell quality issues.

Common Egg Shell Quality Problems

  • Dirty egg shells
dirty brown egg with chicken feces on it

Raising chickens and/or ducks, you will on occasion get some dirty eggs, especially if a heavy girl accidentally breaks an egg. Then you get hay/straw all over it, which makes it a sticky, nasty mess on the rest of the eggs.

But if you are regularly getting dirty, soiled eggs, then it could mean there’s too much salt, electrolyte issues, and/or indigestible food causing wet droppings. (Or you could have a duck that constantly leaves a dirty mess, because that’s what they do.) Moving on.

If you’re regularly collecting dirty eggs, then collect them more often. And avoid foods that cause wet droppings. Also make sure your birds aren’t getting soft water (from a water softener), because it could be giving them too much salt.

  • Wrinkled egg shells
wrinkled, brown egg

Eggs that have wrinkles or thin creases on them are typically referred to as wrinkled eggs. Some other sites also refer to them as corrugated egg shells. And this can be caused by stress, including heat stress, a defective shell gland, poor diet, and infectious bronchitis.

So while perfectly safe to eat, if it’s a one time thing, it’s nothing to worry about. Your hen probably got spooked by a dog barking, or she got too hot. If it continues, check your coop out and make adjustments as needed, if there’s not enough ventilation or there’s over-crowding. However if any of your birds look ill, call a veterinarian.

  • Shell-less eggs

This is another issue that first time egg layers can face. But it can also be seen by other members of your flock. And other culprits can be stress, some vitamin and mineral deficiencies, too much salt, and illness.

The first thing you want to do is make sure your backyard birds are getting enough calcium by offering them free choice oyster shell. However if the problem persists, check for possible stress in your flock, and the salinity of their water. And don’t forget to look them over for respiratory problems. Though you may need to call the vet if all else seems good.

  • Soft-shelled eggs

Stress, dietary imbalances, and lack of calcium causes soft shelled eggs. Most of the time the stress is in the form of hen-pecking, but it could be a neighbor’s dog running into the hen house while the hen is laying. The birds can be fine, because you rescued them. However it’s still stressful. And it will show up in their eggs and shells.

So, as with the one above, make sure you’re giving your birds free choice oyster shell. And feed them high quality chicken feed, reserving treats as a treat only. Don’t make treats or table scraps their source of food.

  • Thin shelled eggs

As hens age, their shells get thinner. So it’s important to continue offering oyster shell. But another cause of thin shells is if you’re giving your hens a lot of treats, therefore make sure you’re giving them a more properly balanced prepared feed than you do treats. If you’re getting thin shelled eggs, lay off on the treats for a while until the eggs normalize.

  • Misshapen eggs
one blue egg, one white egg
The egg on the left is from a chicken, while the one on the right is from our oldest Pekin duck. And Pekins lay very large eggs, so the chicken egg would be considered odd for its size. An older hen probably laid it.

These types of eggs are either too big, too small, too round, or too something else. Just fill it in with whatever you want. And usually this really only matters, for the most part, for large operations that sell to the public. Because, once again, people want uniformity, and if something looks off, they think something might be wrong.

The most common reason for misshapen eggs is that a pullet is just starting to lay eggs. We’ve had a couple of hens that have laid long eggs, and only for a short while. And they were all new pullets. But nothing was wrong with the eggs, except they didn’t look like everybody else’s. If I sold to the public, I’d have to throw them out.

However that’s not the only reason for misshapen eggs. Defective shell glands, stress in the henhouse, and a number of diseases. So if your birds have all been laying eggs for some time, and you run a poultry palace, then call a veterinarian to check for illnesses.

  • Calcium deposits or pimples
darker bumps, calcium deposits on a brown egg

An egg that’s rough with tiny bumps on it has calcium deposits. And the most common reason for it is excess calcium in the diet. Another possible cause is too much vitamin D3 and/or overactive shell gland.

If the calcium deposits are caused by nutritional imbalances, make sure you’re giving your birds high quality, properly prepared feed with free choice oyster shell.

  • Calcium deposits inside eggs

I wanted to include this, even though it’s not on the egg shell. But calcium deposits can show up even inside the egg. And you can mistake them for bug eggs, however they absolutely are not bugs. They’re tiny little beads though! And yes, they’re the same as calcium deposits that occur on egg shells, only these happen inside the egg shell.

  • Speckled eggs
speckled egg

The spots on speckled eggs can be brown or white. And the most common reasons are too much calcium, disturbance during calcification, and/or a defective shell gland.

Although some hens might lay them once in a while, and they’re not necessarily an issue. Except if you were selling to grocery stores.

  • Fairy, fart, or rooster egg
large white egg and tiny dark brown egg
Again the white egg is from our duck while the egg on the right is from a new layer. This was just for size comparison.

This type of egg actually goes by quite a lot of names, but it isn’t any of those things in reality. In truth, the egg is tiny, laid by a first time egg-layer, thus the small size. And it’s nothing to worry about.

When to Call the Veterinarian for Egg Shell Quality Problems

Most of these common egg shell quality problems are due to stress or diet. If a hen is frightened or disturbed while she’s laying an egg, the passage through the oviduct can temporarily stop. This interruption causes a whole host of egg shell quality issues.

For larger operations, this is a bigger deal since odd shaped eggs won’t fit in the same carton. Plus it will be more likely to break in transport. But this isn’t a problem for backyard chicken owners. If your birds get a good diet of quality feed, fresh, clean water daily, oyster shell, and can safely free range, they might lay the accidental weird egg. However if you see consistent abnormalities with their eggs, then call a veterinarian to check for illnesses, especially if more than one bird’s eggs seem to be involved.

This list is certainly not exhaustive by any means. But I just listed the most common ones that I’ve personally seen in my flock or that I’m familiar with. If you’re interested in knowing about all the other issues with egg shell quality, then click here.

Thanks for stopping by! As always, please feel free to comment or ask a question!



I breed pure Black Ameraucana chickens and Easter Eggers that are Black Ameraucana mixed with either Cuckoo Maran or Barred Rock. And I donate eggs to people or organizations in need.

One reply on “Common Egg Shell Quality Problems”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s