What’s That Lump On My Chicken’s Chest? A Tumor?

Every now and then, there are things that happen with my chickens that just make me shake my head in disbelief. From hens that suddenly start crowing to chickens that start laying their eggs in strange places, these fun backyard companions can sometimes be a bit of a mystery.

One such example? When your chicken has a lump on its chest.

chicken lump

If you’re reading this article, you might be doing so in a frenzied panic, wondering if your chicken ate a golf ball or perhaps worse, has some sort of cancerous tumor. Don’t panic, though.

Fortunately, a lump on your chicken’s chest is often nothing to worry about, it is not a tumor, and quite frequently, is just something that’s only temporary and easy to resolve on your own at home.

There are several different things that can cause a lump on a chicken’s chest – but some are definitely more common than others. Here’s what you need to know.

What Causes a Lump on a Chicken’s Chest?

Possible Cause #1: Impacted or Sour Crop

These two problems are some of the most common issues that can cause a lump on a chicken’s chest is an impacted crop. To figure out if this is what’s causing your girl some issues, you’ll want to first make sure it’s actually the crop that is problematic.

The crop is located just beneath the chicken’s neck, right against the breast, near the center or slightly off to the right.

This part of a chicken’s anatomy is absolutely essential. After a chicken swallows food, it goes to the crop, the first stop in the digestive tract.

Now here’s where you need to pay attention…

If a chicken has eaten well and drank plenty of water during the day, its crop will be bulging slightly as it moves out to the roost for the night.

That’s totally normal, as the food is temporarily stored in the crop where it’s dissolved before passing into the gizzard and small stomach. Come morning, however, the crop should be empty. It will refill during the day.

When food remains in the crop too long, several issues can arise. Food that stays there too long can produce yeast, leading to illness and infection.

You’ll know it’s the crop that’s causing your chicken some problems if you feel the lump and smell a bit of an odd aroma coming from this area.

If the crop doesn’t empty overnight, it can cause the crop to “sour” – a condition that is quite literally known as “sour crop.”

Upon closer examination, you might find that the crop feels watery and squishy (and again, smells bad). In addition to this swollen crop, you might find that your chicken develops diarrhea.

There’s a second issue that can arise in relation to the crop, too. This one causes the crop to feel swollen and hard, and it happens when the crop does not fully empty.

Also known as an impacted crop, it is caused by overfeeding too much dry feed, and not giving your chickens enough water.

Interestingly, an impacted crop can happen on its own, or it can cause a sour crop as an additional, secondary condition. Basically, sour crops are when food begins to spoil inside the chicken’s crop.

Possible Cause #2: Breast Blister

The other common issue that can lead to a hard lump on a chicken’s chest is a breast blister. Also known as a keel cyst or sternal bursitis, this lump results from inflammation on the chicken’s keel bone.

It is most common in chickens that are injured or sick and as a result, spend a lot of time lying with all of their weight positioned on their breast bone.

This issue is also more common in meat birds or broilers who cannot stand because of obesity or weight that is gained too rapidly.

It can vary in its severity, from mild to severe, and can cause a long list of other, secondary symptoms, too, such as feather loss, inflammation, and serious blisters filled with fluid.

How to Treat a Lump on a Chicken’s Chest

Do Nothing

In many cases, a sour or impacted crop will clear up on its own. However, in severe cases, it can be uncomfortable for your chicken and it can even lead to death, as your chicken becomes lethargic, fails to gain weight, and moves its head in strange ways in an effort to alleviate the buildup of gas and pressure.

A severely impacted or sour crop can be completely solid – meaning it can block the chicken’s entire digestive system. Plus, the food that’s trapped there isn’t doing your chicken any good, as it’s not only providing zero nutrition, but it’s preventing your chicken from eating anything more.

A bad case of sour crop can also cause your chicken’s digestive tract to be flooded with added yeasts and bad bacteria. This can, essentially, poison your chicken.

If you notice a hard crop, wait it out for a day or two. If the crop still feels hard after this time, you’ll need to take additional steps to help resolve it – it’s probably not going to clear on its own.

Treat Wounds

If it’s a breast blister that’s giving your chicken grief, you’ll want to treat the wound that caused the blister in the first place. Clean off the wound, and use a mild antiseptic.

You can also treat it with a wound dressing spray, like Blu Kote. Keep the area clean until the blister has healed.

You might also need to isolate the chicken from the flock during this time. Chickens often lash out aggressively when they notice that other birds in the flock are suffering from any kind of injury – particularly if there is any blood or exposed red areas.

You might need to pull your chicken from the flock and give it a warm, soft area to get comfortable.

Use Antibiotics

If you are sure that it’s a breast blister that’s causing the hard lump, you will want to treat with antibiotics. These might be necessary to prevent an additional secondary infection if the blister has caused the skin to break.

In the future, you can prevent this by giving your chickens soft areas to rest on. Use a soft bedding or padding, and replace any damp bedding materials as quickly as possible. That way, your chickens won’t be resting on them for long periods of time.

Withhold Feed

Step number one in clearing up an impacted crop is withholding feed. Your chicken might still try to eat, even with the impacted crop, and it’s not going to be doing any good. Isolate your bird and withhold feed (but not water) for a couple of days.

Your chicken might be eating well yet still functionally starving. If the food is coming out of the chicken in almost exactly the same form it went in, you have some kind of problem.

Olive Oil or Apple Cider Vinegar

Apple cider vinegar, when added to your chicken’s water supply, can help clear up a sour crop and break up an impaction. Just add one to two teaspoons of apple cider vinegar per cup of water. It should help cleanse the crop and restore balance.

Remember that a sick chicken might not feel up to drinking, so you’ll need to offer liquid frequently. You may also need to “force” it by using a dropper or syringe – but be gentle when trying to get your chicken to drink so that you don’t make her feel any worse.

One other word of caution – if you are adding apple cider vinegar to the drinkers, do not do so in a galvanized metal container. This can cause metals to leach from the drinker, which can make your chickens sick.

Otherwise, it does not hurt to add apple cider vinegar to your chicken’s regular drinking water supply. Your other chickens will benefit, too, as apple cider vinegar contains helpful probiotics and enzymes that can improve their overall health, and even help keep internal parasites and other diseases at bay.

Some people also use olive oil, which can help lubricate the blockage enough to allow it to dissolve and pass through. However, this won’t provide the same dose of probiotics and nutrients as apple cider vinegar, so just keep this in mind.


Massaging your chicken’s chest as gently as possible is another good way to help loosen up any impaction.

Do not do this if you suspect a breast blister or another issue with your chicken – it should only be done for an impacted crop. Massage a few times a day for a few minutes at a time until you feel the blockage loosen.

Preventing Chicken Chest Lumps in the Future

Consider Breed

Although sour crop and impacted crop can happen to just about any breed of chicken, breast blisters almost always happen to fast-growing meat or broiler chickens, like Cornish Cross birds.

If you find that a “lumpy chest” is something that keeps occurring in your flock, you may want to consider raising a slower-growing chicken breed instead.

Consider Feed

Chickens who are given access to plenty of fresh water and good food during their waking hours shouldn’t have any issues with their crops.

You can improve crop health by making sure your hens are given access to good-quality feed along with greens, vegetables, and fruits, which will add fiber and beneficial digestive enzymes that can help with digestion.

You may also need to up the grit that your chickens are given. If you raise your chickens in confinement, make sure you use a store-bought grit to help your birds grind up their feed in their crops.

Often, chickens that are raised on pasture do not need supplemental grit as they’ll eat plenty of small rocks and other “hard” materials to help do this job instead.

Avoid Antibiotics

There are many potential causes for a sour or impacted crop besides feeding inadequately, too. Oral antibiotics can cause digestive problems, particularly strong broad spectrum antibiotics.

These will kill off good digestive bacteria along with the bad, making it more challenging for a chicken to naturally process food and absorb beneficial nutrients.

If you must use antibiotics to treat any kind of illness in your flock, you will want to make sure you are replenishing the good bacteria with probiotics. You can use a probiotic powder or liquid supplement, like Rooster Booster, or even provide natural probiotics with live culture yogurt.

Avoid feeding options that are overly sugary, as this can cause yeast to multiply out of control. The occasional treat or sweetened yogurt is okay, but too much can lead to serious problems.

Prevent Parasites and Diseases

A bad parasite infestation can occasionally lead to a lumpy chest, too, so it’s important that you take steps to prevent parasites in your flock. Usually, it will be internal parasites that cause problems.

You can prevent internal parasites by using natural dewormers like apple cider vinegar and garlic. Internal parasites when left untreated, can cause an impacted or sour crop, as well as lethargy (which can lead to a breast blister).

External parasites like mites and lice can also lead to general malaise which can cause your chicken to develop a lumpy chest.

Keeping the coop clean is a great first line of defense at preventing both internal and external parasites, as is providing plenty of clean, fresh water and nutritious feed.

Even disease can lead to a lumpy chest. Problems like egg peritonitis, an E.Coli infection in a chicken’s reproductive system, can slow digestion and lead to sour crop.

Maintaining good flock hygiene and treating signs of illness immediately can help prevent sour or impacted crops from becoming issues.

Treating Chicken Chest Lumps – My Experience

I was fortunate that the lump on my chicken’s chest went away in just a day or two – I think it was just a slightly enlarged crop.

Again, wait it out for a short period of time to see if it goes away, but if it doesn’t, one of the solutions above might prove to be helpful as you figure out the issues for your own flock of chickens.

Remember to always consult a veterinarian if you can’t figure out what’s going on with your chickens. They will be the best source of information when it comes to addressing, treating, and healing your girls. Good luck!

chicken lump Pinterest image

6 thoughts on “What’s That Lump On My Chicken’s Chest? A Tumor?”

  1. Glad I came across your article. My young chicken started having bad diarrhea, and I thought maybe from too many mealworm treats. After isolating her I just happened to feel her lump in the front and googled it and came across your article. So, I did put some ACV in her water and removed her food. If it’s her crop. Problem solved. I didn’t know to look in that direction. I’m still learning. Thank you.

  2. We just experienced a sour crop with one of our 3 month old chickens. I think I figured it out too late. My husband worked on her and got a lot of the sour food out and we thought she was better. Then she just died. He thinks he did it for too long (not taking breaks) and maybe she suffocated . She had the bulge yesterday and I should have acted on it sooner.😞

  3. Thank you. Our chicken definitely has a lump – looks like an impacted crop. Very relieved to have an idea of what might be going on.


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