Foot Fails
Bumblefoot can become a serious, life-threating disease, so take precautions to avoid it when possible.
Bumblefoot can become a serious, life-threating disease, so take precautions to avoid it when possible.
Bumblefoot is a problem many backyard chicken-keepers have heard about and have fears they may encounter it in their own flock. 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.
LEVELS OF SEVERITY
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. 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.
Bumblefoot has various levels of severity, 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 I: The surface skin cells (epithelium) become thinner, and there are pink, shiny areas of skin with peeling or flaking.
GRADE II: The surface skin cells become even thinner and almost translucent to where the subcutaneous tissue is visible but not exposed.
GRADE III: The surface skin cells have an ulceration through them such that the subcutaneous tissue is exposed.
GRADE IV: Necrotic tissue is present within the ulcer.
GRADE V: Swelling of the soft tissue of the foot is present around the ulcerated and necrotic tissue.
GRADE VI: Tendons become involved in the lesion and can be swollen or damaged.
GRADE VII: Bone is affected.
WATCH YOUR STEP
Bumblefoot can start as a result of various underlying contributing factors. 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, lets 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. Perches should be no more than 21⁄2 feet off the ground. Additionally, the substrate they are walking on should not be firm.
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 where you are located, one of these substrates may be better than another for your flock, and other factors should be considered such as humidity levels and temperature. Substrates that are inappropriate and can contribute to bumblefoot include flat surfaces, concrete or coarse, large rocks. Avoiding these can help a chicken-keeper avoid bumblefoot.
CLEANLINESS MATTERS
Another factor to consider regarding the substrate is the cleanliness of the area where a chicken is standing. Surfaces soiled with feces mean that a chicken’s foot could be in contact with waste products such as ammonia that can damage the skin.
Substrates that trap and hold moisture may also be 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.
DIET DECISIONS
Nutrition can also play a role. One nutrient that is known to be a problem and can contribute to the development of bumblefoot in birds is vitamin A. 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, thus contributing 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.
One other nutritional problem that can be seen and allow for a bird to be more prone to the development of bumblefoot is when a bird is overweight. 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, which just means the bird suffers longer and may not even heal. Therefore, providing birds appropriate amounts of feed and getting them the right exercise can help prevent bumblefoot.
Bumblefoot has various levels of severity, 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.
TREATMENT
Treatment will vary depending on the grade of bumblefoot that is present. Milder cases, such as grades I and II may be able to be managed with anti-inflammatories, changing substrates and providing padding to the feet. The best treatment will be dependent upon what the cause is for the individual bird that has bumblefoot. 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 and provide a cushioned surface that protects the pad of the foot 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 they can be taken off for the applications of topical medications or cleaning of 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 and 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% or diluted iodine solutions can be helpful as well. Sometimes Epsom salt is used to soak a chicken’s foot in to help reduce inflammation.
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 antibiotic resistance issues are avoided and drug passage into eggs can be discussed. People who could be sensitive to antibiotics need to be cautious if they consume eggs from a bird treated with antibiotics. An avian veterinarian should be contacted for help with all medications, special bandages and surgeries that need to be performed.
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 problems are discovered in your flock; he or she has the experience needed to guide you through an appropriate treatment plan.
Veterinarian Stephanie Lamb practices in Arizona in the greater Phoenix metropolitan area. She is a boarded specialist in avian medicine and gets to care for all different species of birds, but chickens are one of her favorites.