A Look at Chicken Leg Health and Anatomy
Reading Time: 5 minutes
By Tove Danovich
If you’ve ever tried to catch a chicken, you know that they can move fast for birds that seem so awkward when they run. The average chicken can run nine miles an hour (much better than they can fly), outpacing some dogs in a race. While a chicken’s feet might scratch up the garden and their feathers and eggs get the compliments, a chicken’s legs often get overlooked. (They’re at least notable for being the part of the bird that most reminds their owner’s chickens are a dinosaur’s distant cousin.) This is a shame — both because there are so many interesting things the legs can teach us about bird anatomy and because there are many issues that might affect your chickens’ legs and are easily treatable if you know what to look for.
A Little about Chicken Anatomy
One common question that comes up when people first see a chicken walking around is, “Why do their knees bend backward?” The joint that appears just under their fluffy pantaloons seems analogous to the human knee except for one thing: it bends the leg forwards. But if you look more closely at a chicken’s skeleton, you’d discover that those downy pants are actually ankle-length instead. Their femur (thigh bone) is hidden under their feathers leaving the shin, feet, and toes on display. A chicken’s skeleton may seem very different from a human’s but most living creatures are a bit like Lego creations — we might look and act differently when put together but we’re all made of the same bricks.
That, of course, doesn’t mean chickens don’t have some special adaptations. If you’ve ever noticed your chickens standing on one leg in wintertime, you might have wondered why your bird suddenly turned into a flamingo when the weather got cold. Or why, if the birds have to rely on a thick feather coat to stay warm, they’re able to walk around in the snow with little issue. There’s one answer to both questions.
While we have to put on a thick pair of wool socks, chickens (and most birds) have a built-in way to keep enough blood-flow in their feet to prevent frostbite while keeping the rest of their body at a toasty 106 degrees Fahrenheit. It all comes down to something called the rete mirabile or “wonderful net,” a fine web of arteries that puts the warm blood flowing from the arteries in close contact with the cold blood coming back from the feet. “The newly cooled blood in the feet lowers heat loss from the feet, and the warmed blood flowing back into the body prevents the bird from becoming chilled,” The Cornell Lab explains in an article titled “Why Don’t Birds Get Cold Feet?” Birds’ feet (and legs) actually do get cold — it just doesn’t transfer much of that cold to the rest of the body. Still, if a hen is ever too chilly and needs to warm up, she’ll simply tuck a leg into her body and let the blood warm up again.
On a dangerously hot day when you need to cool down your bird, placing their feet and legs into cool water can also help bring down their internal temperature using the same physiology.
Why Can’t My Chick Stand Up?
Though there are leg issues to look out for as your chickens grow up (like scaly leg mites or a broken bone), the first one most people encounter is something called “spraddle” or “splay” leg which usually shows up within a chick’s first few days of life. The symptom is exactly what it sounds like — legs that splay out to the sides of the chick rather than sitting beneath their bodies in serious cases. In mild cases, the chick might have a wider-than-average stance though still be able to walk. It’s worth treating regardless. Splay leg can be caused by incubator or vitamin deficiency issues but, commonly, it’s a result of poor bedding choices that prevent the chick from getting enough grip to allow the legs to develop properly. This is why people recommend against brooding on a slick surface like newspaper. (I like to use paper towels over bedding material for the first few days at least; this also keeps them from thinking the bedding is food and eating it, and I have successfully avoided splay leg in my flock.)
Regardless of the cause, treatment is the same and, without fixing, splay leg can prevent the chick from walking and can be fatal if the chick can’t move to keep itself warm or get to the feeder and drinker. Luckily, it’s very treatable with some vet wrap and a little chicken physical therapy. Just splint the chick’s legs so the chick is forced to keep his or her legs at the right angle and encourage the chick to walk to help the muscles strengthen in the proper position. (Do frequent check-ins to make sure the chick is getting food and water doesn’t hurt.)
There isn’t one right way to splint a chick’s legs together. The important part is that each leg is wrapped with some kind of spacer between them to prevent the legs from getting too close or too far apart. I’ve seen people make a spacer out of a cut piece of plastic straw put over a rubber band or hair tie (with the ends of the rubber band looped around the chick’s legs so it looks like a tiny pair of handcuffs). Others use vet wrap, which has the advantage of being sticky enough to self-adhere while remaining easy to remove. Another common method is to take a Band-Aid and use the white center as the “spacer” while wrapping each leg with the sticky end. The latter can be difficult to remove without bothering your chick so be gentle, but it is better than not treating at all.
It’s important to set your growing chickens up for success so treating issues that crop up when they’re young will help them heal quickly and set them on a path to proper development.
Examples of Different Splay Leg Treatments:
Originally published in the Backyard Poultry Special Subscriber 2020 issue — Comb to Tail Health — and regularly vetted for accuracy.