Recognizing Cold Stress in Chickens

Cold stress is often an overlooked aspect of winter chicken keeping due to the fact that chickens generally handle cold weather better than warm weather. However, cold stress is almost always present in the flock during the winter, it’s just a matter of determining when that stress becomes detrimental to the health of your flock. Recognizing cold stress in chickens is important for monitoring the health and comfort levels of the homestead flock this winter. I am always on the watch for these signs and symptoms that tell me how well my flock is enduring the northern Michigan winter.

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Can Cold Stress Kill?

First, let’s answer this important question, can cold stress kill a chicken? Yes, it can. Chickens can freeze to death. Stress levels can become so high that the body focuses on trying to stay warm instead of other important functions. Other health ailments combined with cold stress can tax the body too much and result in death. Handled alone, the chicken may have been able to fight the ailment or handle the cold, but when combined, cold stress and another health ailment can really zap the energy from a chicken. So, yes, cold stress can become fatal.

That being said, fatalities often occur only under extreme conditions. Recognizing the signs and symptoms of cold stress in your chickens is essential to knowing how much cold stress your flock is dealing with at any given time. Most of the time you will be able to implement preventative measures so that the cold stress levels don’t become fatal.

The most common reason why cold stress causes death is when it is combined with another pre-existing health ailment or injury. Doing a monthly health check on your whole flock is a good idea to give you an assessment of where your flock is at health-wise every month. During the winter, watch out for these issues that can compound the affects of cold stress:

• internal parasites
• respiratory issues
• diarrhea & pasty droppings
• coccidiosis
• improper diet

Keeping a healthy flock is one way to prevent cold stress from becoming fatal. The other way is being able to recognize different levels of cold stress in your flock.

Signs of Cold Stress

Like I mentioned above, recognizing cold stress in your flock is essential to keeping them healthy, happy, and comfortable this winter. One way to assess the affects of cold stress on your flock is to watch for the signs and symptoms of varying degrees of cold stress.

How your flock behaves and interacts with each other on a daily basis can tell you a lot about how they are doing physically. The degree to which your flock is experiencing cold stress will show in their behaviors and actions. I have divided up the signs and symptoms of cold stress into two categories, signs that indicate minor cold stress and signs that indicate severe cold stress.

Watch for these signs to evaluate the amount of cold stress your flock is experiencing.

Signs of Minor Cold Stress

Fluffed Feathers

A chicken’s first line of defense against the cold is its feathers. As the temperatures drop, chickens will try to conserve their body heat. One way that they do this is by fluffing up their feathers. The air trapped in-between the feathers then gets warmed by their body and acts as an insulator.

This feather-fluffing method of conserving heat means two things. First, chickens don’t benefit from sweaters. While they may be cute for pictures, they will not help your chickens stay warm. The sweaters flatten down the feathers and don’t allow air to be trapped and heated next to the skin. Second, dry coop air is important during the winter. Moisture laden air takes more energy to heat up and makes it harder for chickens to conserve body heat.

Feather fluffing is a common sign you see as your flock adjusts to cooler fall and winter temperatures.

Perching

Prolonged periods of perch time is another sign that your flock is dealing with some minor cold stress. As your flock attempts to conserve energy and heat, they will spend more time perched in sunny, warm spots if they are available. This allows them to utilize more energy towards staying warm. It also gives them the chance to cover their legs and feet with their breast feathers to keep those appendages warm too.

There is a fine line between perching for conserving heat and lethargic perching. If a chicken is unwilling to leave its perch for food, water, and other necessary activities, then it is showing symptoms of something more serious. This could mean more extreme cold stress or another disease or ailment.

Periodic perching throughout winter days is perfectly normal for your flock as they deal with minor cold stress. Make sure you have some nice perches placed in sunny but protected spots for them to enjoy. Just keep an eye on your birds to ensure they are still willing to get active and moving around for treats, boredom busters, daily food, and water.

Inactivity

As colder weather sets in, you will notice your flock becoming a little less active. I know that when I give my flock the choice to free-range during the winter, they seem to prefer to hang out right around the coop. Their free-range activities are much more subdued compared to the summer.

This decrease in activity is allowing your flock to conserve energy again. It all comes back to conserving energy so that they can focus energy towards the additional need of staying warm. A decrease in activity is normal, as long as it doesn’t lead to lethargy.

Decreased activity in the flock may appear in several ways. They may spend more time standing around, huddled together to share warmth and conserve energy. More than likely your flock will spend more time around their feeder too, since it is a source of energy for staying warm. They will be less likely to expend extra energy in doing normal activities like preening, dust bathing, or foraging.

That’s one reason why staying on top of external parasite prevention is especially important during the winter. However, you can encourage your flock to engage in their normal activities by providing them with extra energy sources and stimulating circumstances. For example, throwing a handful of high-protein scratch into some straw encourages your flock to get active (forage in the straw) while providing them with the extra energy they need to be active (high-protein treat).

Signs of Extreme Cold Stress

Shivering

If a chicken cannot conserve enough heat, their internal body temperature will start to decrease. This causes them to start shivering, which is the body’s natural response to a decrease in body temperature. Shivering is meant to stimulate the muscles and expend energy to generate heat. Shivering is the first sign you should watch for that will indicate your flock, or an individual bird, is experiencing more extreme cold stress.

With chickens, you can usually visibly see them shivering. Watch past those fluffed out feathers and you may be able to see a slight shaking or occasional tremor. Since shivering expends more energy, it means the chicken is using up reserve energy sources. These reserves are usually in the form of fat, but once that fat is used up, the body starts drawing from other more essential reserves, which can be dangerous.

Lethargy

Lethargy usually comes after a period of shivering. It occurs when the body has resorted to mainly focusing on staying warm and generating heat. A chicken will stop moving, and not want to move, when they are lethargic. Moving expends energy, which is something that is in high demand when a chicken is experiencing extreme cold stress.

Do not mistake periods of perching or huddling to be lethargy. The key to knowing when a flock member is being lethargic due to cold stress is watching for other behaviors. Shivering will usually accompany cold stress lethargy as well as being unwilling to move regardless of the reason, whether it be from being pecked at, needing food or water, or being enticed with treats. A lethargic chicken will not want to move and expend energy that is being used to try and maintain a proper body temperature.

Lack of Interest in Food or Water

A chicken can be lethargic but still willing to eat and drink when the items are placed in front of them. Extreme cold stress is taken one step further when a chicken no longer becomes interested in food or water, no matter how close and accessible they are.

While I don’t know specifically what causes a chicken experiencing extreme cold stress to loose interest in food or water, I could probably guess it has something to do with energy and body functions. It could be the body is simply functioning at its lowest level and is not sending the correct signals for hunger and thirst. Even though food and water are needed for survival, they are not a priority when the body starts choosing functions to shut down.

Frostbite

Lastly, frostbite can also be a sign of minor to extreme cold stress. Frostbite can occur at any stage of the cold stress scale. This is because frostbite is not caused by cold stress alone. Frostbite is mostly caused by moisture, which freezes next to the skin. However, frostbite can be caused or expediated by the presence of cold stress.

Cold stress will cause a chicken to start restricting circulation to the parts of the body that help it stay cool in the summer, namely the comb and wattles. Feet and toes may also be affected when cold stress increases or exposure plays a role. Reduced circulation allows those appendages to freeze. Frostbite is painful for chickens and can cause additional stress due to the pain.

Severe frostbite can also lead to infection, lose of appendages, and sometimes even death due to gangrene. Remember though, frostbite is not always a sign of cold stress, it can also mean the ventilation in your coop is not adequate or your chickens are not protected enough from winter weather exposure.

When to Help

So, you know the signs and symptoms of cold stress. They can be exhibited by individual chickens or by the flock as whole. You can even tell when your flock is experiencing minor cold stress or extreme cold stress based on their behaviors. But what good does this do you if you don’t know what to do about it? When should you step in and help your flock deal with their cold stress?

Good question! First, remember that not all stress is bad. Minor cold stress will occur as your flock adjusts to colder temperatures or if they experience periodic extreme weather throughout the winter. A flock that is managed well and is healthy will naturally deal with spells of minor cold stress on their own just fine. They can implement measures such as fluffing up their feathers and conserving energy to make it through until they either adjust to the cold temperatures or the weather stabilizes and goes back to the ‘normal’ they were previously adjusted to.

Once the cold stress levels start to increase is when you may consider stepping in to help. If you know what your flock’s average critical low temperature is, you will have a general idea of when the cold stress levels may increase. I talk more about the average critical low for a chicken in my post Cold Stress 101. Once the external temperatures have reached your flock’s critical low, you may start to see signs of extreme cold stress.

When a chicken’s body starts to resort to last ditch efforts to stay warm and conserve energy is when you should step in to help. The degree to which you help will be determined by the degree of cold stress. Here are a few pointers:

Tips for Helping Chickens with Cold Stress

• minor cold stress signs- provide high energy treats, encourage activity but provide the extra energy source needed for expending the energy, ensure proper protection from exposure
• shivering- provide more high energy foods, consider providing free-choice heat
• lethargic- provide supplemental heat
• lack of interest in food or water- move to a warm infirmary pen for more intensive care
• frostbite due to cold stress- encourage activity to stimulate circulation, provide supplements that stimulate circulation
• severe frostbite- move to an infirmary pen for more intensive care

Keep in mind that symptoms such as inactivity, lethargy, and lack of interest in food or water can also be signs of other health ailments.

Recognizing cold stress in chickens is an essential winter chicken keeping skill! Being able to tell what degree of cold stress your flock is experiencing will enable you to care for them better and meet their winter time needs. In some cases, recognizing extreme cold stress could save a flock member’s life. Chickens will exhibit different behaviors depending on their needs, which during the winter is dictated by the new need to stay warm enough. I enjoy watching my flock during the winter to gauge when I can help them stay healthy and warm!

If you want weekly advice for caring for your flock this winter, make sure you are a part of our weekly pioneer newsletter community! Also, make sure you get your copy of our ebook, The Complete Guide to Winter Chicken Keeping!

Warm wishes from the flock!

by Alexa