Pasty Butt : What it is, who gets it and how to spot, treat and prevent it.

Just hatched chicks and wondering what all the fuss over pasty butt is about? 

It's a problem you may never have to deal with - but you need to know about it just in case.  Pasty butt can kill!

Here's all the information about it you'll ever need : what it looks like, where you'll find it, how to spot it,  what you need to do and how to prevent it happening again.

Here's what I cover on this page.  Click on any of these links if you want to get to a particular section quickly.  Otherwise just scroll down the page as normal.

What exactly is pasty butt?

Pasty butt, also known as 'pasting up', is the vent hole of a chick - the place where poop and urates (the chicken equivalent of urine) come out - becoming clogged up with hard (or 'pasty') stools which stick to the chick's downy feathers and don't come off by themselves. 

It's as simple as that.

Who gets it?

Normally very young chicks.  It's particularly common in chicks who've been sent by mail.  It tends not to happen in chicks who've been hatched and raised by a broody hen because she'll take charge of making sure her babies are kept clean and healthy.

A broody hen will usually take care of pasty butts herself.

A broody hen with chicks.

When you've hatched in an incubator or when your chicks have come by post and are going into a brooder, you must take the place of the mother hen. 

No matter how distasteful it my seem to you, you need to clean the chick up yourself - a baby chick isn't capable of doing this alone!

Is it important?

Critical - and it won't go away by itself.

It's important because if a chick's vent becomes blocked with stools, it can't poop.  As a result, its insides become blocked and it will die fairly quickly.

How to spot it.

If you have ordered your chicks to be sent by mail or you've bought from a feed store, you need to check each one of them as you put them into your brooder box.  If you've hatched yourself, check each chick as you take it from the incubator.

In either case the signs are exactly the same.  Hold the chick between your thumb and first or second finger.  Turn it over and look at its behind.  If it has pasty butt you'll spot it straight away - a matted lump of usually dark brown stools attached to its backside.

Close up view of a pasted up vent

You need to check your chicks regularly - pasty butt is most common in the first week or two of a chick's life as it becomes used to its surroundings and food. 

Some symptoms you might see in affected chicks are :

  • Lethargy - chick seems to be weaker than the others
  • No / slow growth
  • Not eating or drinking
  • Not sleeping
  • Protruding vent

- but it's really better to catch it before it gets to this stage.

I can see two holes - which one is the vent?

Don't confuse the vent with the chick's belly button and umbilical chord.  The vent is immediately below the tail feathers.

Look for pasty stools under the tail feathers

The belly button is higher up, between the vent and the chick's legs.  You may see a raised reddish or pinky coloured bump which is caused by the yolk the chick has absorbed immediately before hatch.

The umbilical chord - exactly as in a human baby - comes from the belly button.  The chord itself will look like a piece of dark coloured cotton. 

Don't touch it - you risk (not to put too fine a point on it) pulling the chicks bowels out.  It will drop off by itself in a day or two.

What causes pasty butt?

There can be a number of factors.  You need to assess your own situation to decide which is most likely and therefore what you need to do about it.

Stress : Chicks sent by post frequently experience stress, as do chicks who don't have enough space in their incubator or chicks who are frightened by - for example - loud noises or frequent handling, particularly by over-eager children.

I realised these day old chicks were huddled together in the brooder because my dog had been sniffing around them.  She wouldn't have done them any harm - but they weren't to know that!

Day old chicks huddled together in brooder.

Cold :  Chicks who are chilled can develop pasty butt.  Often, chicks sent by post will experience this as they go through various stages of delivery in different locations and can sometimes be left hanging around in cold depots for several hours.

Heat : Overheated chicks can develop pasty butt.  This is most common in brooders with hanging heat lamps, particularly if the chicks are crowded together and don't have enough space to move away from the heat source.

Food :  Chicks are cute.  Inevitably, you'll want to give them treats.  But chicks who are a day or two old can't process anything other than a good quality chick starter feed. 

How to treat it?

You need to remove the hardened poop with as little damage to the chick's down as possible.  Being too rough can pull out the down which can make the chick chill very quickly - and cold can kill them.

Here's a step by step guide to treatment as I deal with it - it may be gross, but it's not difficult! 

Always wash your hands before and after handling chicks or chickens.

I make sure I wear disposable gloves for this both to make sure I don't transmit any bacteria to the chick and to make sure the chick doesn't give me any!  If you haven't got disposable gloves to hand, just make sure you wash your hands thoroughly before and after.

You'll need :

  • The chick
  • Some disposable gloves
  • Warm, running water
  • Some cotton wool or cotton buds
  • Some Vaseline (petroleum jelly) on standby.

    1.  Hold the chick between your thumb and forefinger with its butt pointing outwards.

    2.  The chick will not like this - who would?  Ignore the cheeping - she doesn't understand it's for her own good!

    3.  Run the chick's butt under lukewarm water - NOT cold.  Make sure the stream isn't too fast.

    4.  At the same time, very gently wipe the poop with a piece of cotton wool or a cotton bud. 

    5.  This may take some time if the poop is very hard.  Work as quickly as you can, but don't be tempted to pull - you'll pull the downy feathers away which will hurt and run the risk that she'll chill.

A nice, clean vent will be pink once it's cleared of pasty stools.

A cleaned up chick following pasty butt

6.  Once all the poop is gone, wrap the chick in a towel to dry off the worst of the water. 

7.  Now put your hair dryer on a slow setting and on warm - not hot.  Use it to dry wherever the chick has got wet, in particular its butt.  The chick needs to fluff up again before you put her back into the brooder. 

8.  Using a hair dryer I've found very effective in hiding the redness of the backside from other chicks.  Red attracts pecking and if the chick is left with a large red area exposed, chances are she'll be pecked.

All fluffed up with a blow-dry and ready to go back into the brooder.

Almost dry after cleaning off pasty butt

9.  If pasty butt happens regularly and the area looks very sore, gently putting some petroleum jelly (I use Vaseline) on the area can help.  I don't use olive or vegetable oil which some people recommend as it can turn rancid in the heat of a brooder.

10.  If a number of chicks have pasty butt, or if one chick gets it regularly, check out the reason (or reasons) it happens and take steps to prevent it.  It should stop by the time the chicks are a week old.


No matter how you try to avoid it, some of your chicks are likely to get pasty butt at some point.  You can try to make sure they don't by following these simple guidelines.

1.  Brooder temperature :  Newly hatched chicks can become chilled or too hot very quickly, and both can kill.  For the first week post-hatch your brooder box needs to be maintained at a temperature of around 32 - 35ºC (90 - 95ºF).  

2.  Learn to spot chilling or over-heating : You don't necessarily need a thermometer to tell whether your brooder is too hot or too cold.  Your chicks will tell you. 

  • Chicks who are too cold  will huddle together under the heat source and cheep loudly. 
  • Chicks who are too hot will try to get away from the heat source so you'll see them spread out around the sides of the brooder box.  They may also be panting (chickens don't sweat, they lose heat through their beaks) and you may notice that their heads are droopy.

3.  Use a good quality heat source : I use a heat lamp which provides radiant heat - see my review of it here.  It provides just enough warmth for chicks without ever running the risk of burning them - or their brooder box.

Two of my day old chicks enjoying the warmth of a Brinsea EcoGlow 20 brooder lamp.

Two day old chicks under a Brinsea brooder lamp.

4.  Avoid stressful situations : If you've bought day old chicks, either from a store or by mail, get them into a nice warm brooder as soon as you receive them - and make sure your delivery service knows not to leave them standing in a depot.

5.  Give them enough space : You will be amazed how quickly chicks grow. For the first week in the brooder box each chick will need about half a square foot of space - the chicks' behaviour is your best indicator of whether they have enough.

6.  Food and water :  Make sure your chicks have access to clean, fresh water.  Don't be tempted to feed them any grain at such an early stage except for a good quality chick starter. 

7.  Treats :  If and when you do start to give your chicks treats, make sure they have some grit.  Chicks (this goes for adult chickens too) don't have teeth - they need grit to help them grind up any food other than chick feed.

These two week old chicks had just polished off a plate of hard boiled egg!  Note the large bowl of grit on the left hand side.

Three week old chicks.
  • Top Tip : For baby chicks, grit can be as simple as sand, a clump of weeds with soil still attached, or alternatively a fine grit from the feed store.  Don't mix it in with their food, provide it in a separate dish - the chicks will instinctively take what they need.
  • Don't mix this up with oyster shell - that's for chickens who've started to lay only.  Giving it to young chicks will damage their kidneys.
8.  Hard boiled egg :

If pasty butt continues, try giving your chicks a little hard boiled egg, well mashed up, making sure they also have access to grit.   But remember that above all,  you need to identify what's causing the pasty butt in the first place.

Having problems with newly-hatched chicks?  Let me help.

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If you've enjoyed this page, you might find these related pages helpful too.  Click on any of the images to go to the relevant page.

Link to my review of reliable brooder lamps.
Link to my 28-day course in incubating chicken eggs.
Link to book review about hatching and brooding chicks.

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