Why Do Some Chickens Lay Thin Shelled Eggs?

Got chickens and suddenly you’ve found an egg that looks quite unusual? You’re probably worried that your bird is not well and if the egg is safe to eat? Well, the most common condition to affect eggs aesthetic appearance is the thin shelled egg and it is something that you might be able to do something about and you probably shouldn’t eat it and this is why.

Your chickens might be laying thin shelled eggs due to a lack of calcium in their diet. There are many other possible causes including the age of your chickens, a dietary deficiency, an excess of phosphorus in the diet, hens that begin eggs production too early, laying in high temperatures, vitamin deficiency, disease, or even that the hens have become particularly excited during the laying process.

What Is A Thin-Shelled Egg?

A thin-shelled egg or often a “soft egg” is an egg with a shell that is substantially weaker than the shell of the usual eggs. They are soft to the touch and they look conspicuously different to the usual eggs that your chickens lay.

It’s very easy to be surprised and even a little revolted by these eggs as they are odd. However, they are a normal occurrence in egg laying flocks and you shouldn’t panic if you find them, there are many possible causes of this problem and some are within your control and can be treated and others are completely out of your control.

Reasons That Your Chickens Are Laying Thin-Shelled Eggs

Your Chickens Are getting On In Years

One of the most common reasons for a chicken laying a soft-shelled egg is that it’s getting on a bit and there’s a fairly good rule of thumb that you can apply to chickens – the older that they get, the lower the quality of the eggshell strength.

Now, older chickens will have good days and bad days, they won’t always lay soft shelled eggs but they will do it more and more. You may want to retire these chickens from your flock as there’s no youth potion, as yet, for chickens to reverse the damage of the passing years.

Your Chickens Are Young

Oddly, it is also true that when chickens first start laying, there’s a tendency to lay thin shelled eggs and this is probably just their bodies trying to work out what’s going on accompanied by a dietary deficiency (see calcium deficiency below).

The easiest thing to do if a young chicken is laying thin shelled eggs is to look at what they’re eating – at this point, you’ve probably been giving them food designed to facilitate growth rather than egg laying. It’s time to switch them over to the same diet as the other egg layers as this will have more calcium in it.

Give it a few days and this ought to resolve everything. Egg shells are made out of calcium and the more of it your chickens eat, in theory, the more they should lay full bodied shells.

Calcium Deficiency

A calcium deficiency can strike at any time in a chicken’s life and it relates to the dietary consumption of calcium. In essence, most standard chicken foods don’t tend to contain a huge amount of calcium by themselves and thus, you may find that you need to supplement their diet with more.

It is important to note that the absence of enough calcium in a chicken’s diet can be indicative of future problems too and it’s not just their eggs that suffer. They start to leach calcium from their own bones to create the eggshells (even if those shells aren’t great) and that is likely to cause major health problems and possibly even kill them in the long run.

The good news is that you don’t have to spend a fortune of fancy dietary supplements as you might with human beings trying to combat a dietary deficiency – either get some oyster shells or use toasted egg shells and add them to their food. This is both cheap and easy. Just make sure that they’re broken down finely and not in big chunks.

Worm Infestations (Nutrient Uptake Impedance)

Chickens just like all animals are occasionally susceptible to worm infections. Worms will hang out in your chickens’ belly and hoover up the nutrients that can be found there before your chicken can make use of them. It’s fair to say that this problem tends to be more marked when you are feeding the chickens older feed products when the nutrient density of the foodstuff has started to drop in the product itself.

That means you’re going to want to treat your chickens for worms, which, thankfully is pretty easy. Speak to the vet and they will provide you with a standard deworming treatment and follow the instructions and you should quickly find the issue clears up. If not, you may want to try some calcium supplements to get them back up to the level their body’s need.

You’ve Been Handing Out Apple Cider Vinegar

We’re not going to argue the merits, or lack thereof, of using apple cider vinegar in a chicken’s diet but it has become a popular addition with certain chicken owners who swear by the benefits – however, if you do decide to do this, you can’t just keep lashing it on everything – you shouldn’t offer them apple cider vinegar more than once a week.

This is because it can prevent the chicken from absorbing calcium properly in the gut. If you’re giving the chickens apple cider vinegar and seeing thin shelled eggs, you want to dial it back a little – stick to a single dosage a week and never more than 1 part apple cider vinegar to 50 parts water, it’s not supposed to end up as a meal but rather it’s meant as a minor dietary booster.

The Temperature Is Rising

How do you put a chicken off of their food? Many chicken owners will look at you in astonishment if you ask this question because if you have chickens, you know that they love their food. However, one thing you might not know is that chickens aren’t quite as advanced as you are and they can’t sweat – when things get warm, they find life gets more uncomfortable and they can go off their food.

How warm is too warm? Well, it will depend slightly based on breed, but a good rule of thumb is that if it’s over 90 degrees Fahrenheit or 32 degrees centigrade that your chicken is probably too warm. Now, your chicken won’t starve to death but if they’re not eating as much, they’re not getting as much calcium as they usually do.

So, the way to try and counteract this is to ensure they always have access to cool, clean and fresh drinking water, some access to shade no matter what the time of day is and potentially in very hot areas – you might even want to consider a ventilation system (fans are popular but need chicken proofing) to keep your birds cool. If you would like to know how to keep your chickens cool in the summer then head over and read our article all about how to keep chickens cool in the summer.

You should also consider adding calcium supplements even if you aren’t already because this will give them a higher chance of consuming enough to make good eggshells.

The Stress Of A Poor Environment And Overly Excited Hens

Chickens aren’t good with change and there are certain things that take place in the environment that can really mess their laying ability up and this, in turn, can impact on the quality of the eggs that they lay – one major issue is predators and if you find that foxes, weasels, dogs, etc. get in and cause mayhem or death, the chickens are likely to turn out poor eggs for a few days after.

The other big environmental issue is often overcrowding in the coop. Chickens need 4 square feet of space each. If you don’t give it to them, they get stressed and they start to peck at each other (this can even lead to cannibalism) and this will cause them to drop the quality of their egg production too.

Always make sure that there’s enough space for chickens even if it means giving some away or building a bigger space for your flock to live in.

The Stress Of An Overly Frisky Rooster

Some roosters are not exactly the chicken equivalent of Don Juan. In fact, some are essentially the most violent lovers that farm animals have ever seen. These roosters aren’t evil, but they are so clumsy that they might as well be.

After a bout of procreation, the hen is left missing feathers and even bleeding. This, as you might expect, is a deeply stressful experience and the egg laying suffers for it. The best thing you can do is isolate the rooster for a week or so and see if he gets over it and if he doesn’t, it’s time to let that rooster go and get another one that isn’t such a terrible lover.

Infectious Bronchitis

Actually, it could be any kind of disease that leads to a poor eggshell but one particular disease is regularly the culprit and that’s infectious bronchitis and that’s because among all the other systems it disrupts in a chicken’s body – it also interferes with “osteoblasts” and those are the cells that manufacture and repair bone, when they go haywire, there may be no calcium available to build a good quality egg.

The best way to deal with this problem is to take your chicken to the vet and see what they can do for them. Diseases like this are best treated as soon as you catch them so that they don’t spread to the rest of the flock, though, sometimes the vet may want to treat the whole flock anyway.

Egg Drop Syndrome

Yes, this is just as it sounds, a condition which causes a chicken’s egg laying and production to drop off. It is a disease which originates in ducks and geese (which are asymptomatic unlike chickens) and then it can reduce egg laying by up to 40%. The remaining eggs may also be thin shilled.

The bad news is that there is no treatment for this disease and if found you will need to notify the authorities immediately. Other signs of infection include diarrhea and a change in color of the shell and the yolk. The good news is that this condition is very rarely life threatening and your chickens will eventually recover.

Vitamin D3 Deficiency

This is another way for a chicken to end up with a lack of bioavailable calcium in their body, they need vitamin D3, in order to be able to make use of the calcium they do have and just like in people chickens make their own by spending time outdoors in the sun.

However, in places where there’s not a lot sunlight, this can be easier said than actually done. The good news is that vitamin D3 supplements are cheap and easy to administer by adding directly to the food, this may be the best final port of call when you can’t work out what else might be interfering with the quality of egg production.

Excess Phosphorous

Too much phosphorous in their diet can interfere with the uptake of calcium in their bodies, if you’re buying pre-mixed feed, this is unlikely to ever be a problem but if you make your own food for your chickens then you should pay careful attention to the amount of phosphorous you add.

Other Stuff

There are other much rarer issues that might be the problem too – if your chickens have been exposed to toxins, for example, or if they have rarer chicken diseases. If you can’t solve the problem by yourself, then it might be time to call in a vet and get their expert opinion. You can’t diagnose every reason for thin shelled eggs online.

Are Thin Shelled Eggs Safe To Eat?

Everyone wants to know this and while, in theory, there’s no scientific basis for not eating them – we feel that the development of a strong eggshell is meant to protect a chick inside the egg from bacteria and infection. Without that protection, it’s possible the egg is contaminated.

So, we’d recommend that you give them to your cat or your dog or throw them away. That’s because chickens are highly susceptible to carrying salmonella, the bacteria that causes food poisoning, and you really don’t want that for you or a member of your family, do you?

Are Thicker Eggshells Better?

Yes. There’s no other way to look at it. From a chicken owner’s perspective there’s no doubt at all that having a thicker eggshell is always the preferred outcome. It means that you can trust the egg inside is not contaminated and that you can enjoy it with your breakfast without hesitation.

But it’s important to remember that a thin shelled egg is not usually a disastrous result and that with a little care and attention, you can normally get your hens laying thicker eggshells in no time at all.


Why do some chickens lay thin shelled eggs? As you’ve seen this can be for a variety of reasons stemming from stress to health issues. Sometimes, it’s easy to rectify any underlying causes and get your chickens laying well again, other times, it’s really not.

The important thing to remember is that you shouldn’t eat thin-shelled eggs because they can potentially carry salmonella at a much greater rate than ordinary hard-shelled eggs. Feed them to your dog or cat to avoid wasting them but don’t eat them yourself, you don’t want food poisoning.

Darren Black

I'm Darren Black, the owner, and author of AnimalKnowhow.com. I am from Scotland, United Kingdom and passionate about sharing useful information and tips about properly caring for an animal's wellbeing.

Recent Posts