Bumblefoot is a problem many backyard chicken-keepers have heard about and have fears they may encounter it in their own flock of chickens. But what is this disease? Where does it occur? How does it happen? What can a chicken-keeper do to prevent it from happening?
Also known as pododermatitis, bumblefoot is an inflammatory condition affecting a bird’s foot. This disorder can be seen in any avian species but is common in chickens, particularly our backyard flocks. Lesions vary in severity, but in order to understand them better, it helps to understand the anatomy of the chicken’s foot.
About Chicken Feet
The foot of a chicken is made up of similar components to other animals, with slight variations that make it unique.
Chickens are considered to be anisodactyl. This means that they have three toes pointing forward and one toe pointing back. The toe pointing back is considered to be digit No. 1, while digit No. 2 is the inner most front digit. Digit No. 3 is the middle front digit, and digit No. 4 is the outermost front digit.
A layer of scaley, typically featherless skin composed of a thick epidermal layer and a thin dermal layer covers each foot. Deep to this, there is a thin layer of connective tissue called the subcutaneous.
It’s very minimal compared to nonavian species such as mammals. Under this are the muscles and tendons of the foot. Finally, just below these are the bones and joints.
Levels of Severity
Bumblefoot has various levels of severity in chickens, ranging from mild redness and thinning of the scales to ulcerations and damage to underlying muscle, tendons and bone. Different grading schemes have been created to allow a more universal understanding of the extent of a lesion in a particular individual.
Grading schemes are either on a “I to V” or “I to VII” scale. But for the purposes of this article, we’ll describe the “I to VII” scheme. As the grade increases, so does the level of severity.
Grade severity is determined as follows:
- I: The surface skin cells (epithelium) become thinner, and there are pink, shiny areas of skin with peeling or flaking.
- II: The surface skin cells become even thinner and almost translucent to where the subcutaneous tissue is visible but not exposed.
- III: The surface skin cells have an ulceration through them such that the subcutaneous tissue is exposed.
- IV: Necrotic tissue is present within the ulcer.
- V: Swelling of the soft tissue of the foot is present around the ulcerated and necrotic tissue.
- VI: Tendons become involved in the lesion and can be swollen or damaged.
- VII: Bone is affected.
Watch Your Step
Bumblefoot can start as a result of various underlying contributing factors affecting your chickens. Perches, substrate, nutrition and trauma have all been linked to this disorder. Sometimes the reason for the disease is obvious in one individual, while it may not be as clear in another.
Additionally, sometimes multiple issues are present. And all contribute to its development.
To start, let’s look at perches. Although chickens may not spend a lot of time on branches to the same degree that other avian species will, they do like to roost on perches while resting. If the perches are all the same diameter, this can lead to pressure being placed on the same part of the foot all the time.
This constant pressure on the same site can lead to sores, calluses or thinning of the skin at the contact points between the foot and the perch.
If there are splinters on the perch or areas of damage, this can inadvertently injure the foot, leading to the start of an ulcer, puncture or cut. This can lead to the beginning of an infection if bacteria is introduced into the wound.
Additionally, if chickens perch on inappropriate items, such as wires, this may also result in more trauma to the feet. For some birds, if the perches are placed too high or they jump off perches onto firm surfaces, this may lead to injury.
Keep perches no more than 2 1⁄2 feet off the ground. Additionally, do not add firm substrate to the ground chickens walk on.
To discuss substrate further, it’s important to know that various types of substrate can be appropriate for chickens. Wood shavings, hay, fine gravel and sand are all soft enough for the feet of chickens and don’t necessarily contribute to bumblefoot when kept clean.
Depending upon your location, you may choose one of these substrates over another for your flock. Consider factors such as humidity levels and temperature, too.
Substrates that are inappropriate and can contribute to bumblefoot in chickens include flat surfaces, concrete or coarse, large rocks. Avoiding these can help a chicken-keeper avoid bumblefoot.
Another factor to consider regarding the substrate is the cleanliness of the area where a chicken stands. Surfaces soiled with feces mean that a chicken’s foot could come into contact with waste products, such as ammonia, that can damage the skin.
Substrates that trap and hold moisture may also cause a problem and lead to the growth of potential pathogens. If there is a break in the skin for any reason and chickens are standing on contaminated substrates, bacterial organisms could enter more easily and lead to infections.
Nutrition can also play a role. One problematic nutrient? Vitamin A, which can contribute to the development of bumblefoot in chickens. If vitamin A is deficient in the diet, it’ll cause a change at the cellular level to the surface epithelial cells of the foot.
The cells can change shape and become thinner. This contributes to the first grade of bumblefoot developing.
The good news is that if you are feeding your bird a commercial pellet or crumble diet, vitamin A is appropriately supplemented in the mixture. Additionally, several scrapes that people provide to chickens are great sources of vitamin A, such as kale, bell peppers, carrots, squash and sweet potatoes.
Providing one of these as a snack a few times a week is another way to ensure adequate levels of this nutrient are available.
Overweight chickens are also more prone to the development of bumblefoot. Too many calories in the diet, without enough exercise, means a bird can become obese. If a bird is obese, even greater forces and excessive weight bear on the feet.
If ulceration develops, that excess pressure on the foot can interfere with blood flow. Impaired blood flow means poor healing. And that means the bird suffers longer and may not even heal.
Therefore, providing chickens appropriate amounts of feed and getting them the right exercise can help prevent bumblefoot.
Treatment will vary depending on the grade of bumblefoot present. You could possibly manage milder cases, such as grades I and II, with anti-inflammatories, changing substrates and providing padding to the feet.
The cause of bumblefoot matters, though, and will determine the best treatment. More severe lesions could require antibiotics, debridement surgeries, special wraps and even amputations of digits if the underlying bone is involved.
Often, some form of a bandage to protect the bottoms of affected feet is required. Bandages may be light covers or specialized wraps that relieve pressure on certain parts of the foot. There are commercially available booties that pet owners can purchase for chickens to cover the feet.
These provide a cushioned surface that protects the foot pad and supplies comfort for the bird.
These are really great for birds that have foot injuries and help prevent bumblefoot from developing on the uninjured foot. These booties are also really nice because you can take them off to apply topical medications or clean wounds.
Additional treatment modalities can also include laser therapy and medications that dilate blood vessels in the feet. Encouraging exercise can also enhance blood flow to the feet. This may help obese birds lose weight and relieve some pressure on the feet.
Cleaning the bottom of the foot and soaking it in disinfectants like chlorhexidine 4 percent or diluted iodine solutions can help as well. Sometimes keepers will soak a chicken’s foot in Epsom salt to help reduce inflammation.
What to Leave to the Pros
Bumblefoot is a painful condition that can involve some problematic bacterial organisms. Backyard farmers have occasionally attempted to perform surgeries at home, but this isn’t recommended. At-home lancing procedures may remove the infectious material in a foot, but they don’t address the pain a bird can feel and can leave a bird in a debilitated state.
Additionally, a veterinarian should select appropriate antibiotics so that you avoid antibiotic resistance issues. A veterinarian can also discuss ways to avoid drug passage into eggs. People with sensitivities to antibiotics need to stay cautious if they consume eggs from a bird treated with antibiotics.
Contact an avian veterinarian for help with all medications, special bandages and necessary surgeries.
Bumblefoot can develop into a serious, even life-threating, disease so check your birds’ feet regularly. You want to address the problem when it’s in the early stages rather than risk only noticing it when it’s severe.
Also, consult your avian veterinarian when you discover problems. He or she has the experience needed to guide you through an appropriate treatment plan.
This article originally appeared in the July/August 2021 issue of Chickens magazine.
Sidebar: Tips to Avoid Bumblefoot
As the old saying goes, an ounce of prevention is worth a pound of cure. It’s always better to prevent bumblefoot than to be stuck treating this potentially serious disease. Once it begins, bumblefoot can be time-consuming to treat and take weeks to months to resolve. Additionally, some patients will have chronic problems secondary to bumblefoot and attempting to avoid this situation will leave a backyard chicken-keeper happier with their flock.
- Perches for chickens should be variable in their size and thickness so that birds don’t have to put pressure on the same part of their foot all the time. These perches should also be routinely inspected for splinters or damage and have any issues addressed immediately.
- Wrapping perches with protective covering, such as a self-adhesive bandage, can also provide a softer surface for the bird’s foot to contact.
- Chickens should be prevented from perching on wires or objects that provide minimal support for the foot.
- Make sure perches are no more than 2 1⁄2 feet off of the ground and the substrate that they are standing on is soft, clean and appropriate.
- Lastly, providing appropriate nutrition and being mindful of trauma to the feet are necessary to avoid bumblefoot from occurring.
Sidebar: Trauma Can Be a Factor
Trauma is another problem that can lead to the development of bumblefoot. This can occur in a couple of different ways.
One way is that trauma to the foot can incite an opening on the bottom of the foot which can lead to inflammation, secondary infection and the start of damage to the soft tissues, bones and joints of the foot.
Additionally, if a bird injures one foot and it causes them to shift pressure off of this foot, all the bird’s weight then gets put on to the uninjured foot. This increased pressure on the uninjured foot can lead to the same problems that we can see with obesity. Therefore, if a bird does have an injury to a foot, sometimes a soft, padded wrap on the uninjured foot is necessary as well so that the bird has less pressure against hard surfaces to try and prevent bumblefoot.