Science and treatment for bumblefoot (footpad dermatitis)

Bumblefoot: What is it?​

• A bacterial infection that causes necrotic lesions on the foot pad, or less commonly, on hocks and toes.
  • Can be superficial (not deep) to deep
• Characterized by inflammation and ulcers
  • If not treated, ulcer formation, as a result of the condition, may lead to abscess formation and fibrosis, specifically on the hock joint.

Bumblefoot Common Causes:​

• Ammonia in bedding
  • Wet/damp bedding increases ammonia production ( > 30% moisture)
  • Feces build-up increases ammonia
  • Create microenvironment pH 11.
    • Irritation leads to an open wound.
• Captive birds
  • Constant walking on hard, rough, or sharp surfaces
    • Develop small wounds susceptible to infection
• Bacterial infection in open wounds
  • Common strains:
    • Staphylococcus, Pseudomonas, and Escherichia coli (E. coli), with S. aureus being the most common cause of the infection
  • Enters open wound
• Heavy Breeds at risk of infection
  • Larger poultry breeds
    • Cochins, Brahmas, Orpingtons, Jersey Giants, etc.
    • More pressure on chickens' feet.

Identifying Bumblefoot:​

• Swelling, elevated surface in the affected area
  • Creating a bulge or bump
• Rough, red skin
• (Severe) brown or black scab
  • Rough to the touch

• Limping
• Lameness
  • Abnormal stance
  • Inability to properly use a limb
    • In bumblefoot, this is due to pain and abnormal skin tissue

Bumblefoot Prevention:​

• Daily check up on poultry
  • Examination
    • Catch bumblefoot in its early stages
• Dry bedding
  • Clean, no feces
    • Less ammonia emission
• Shaved down wood/surfaces if non-free ranging birds
  • Prevent splinters which can lead to bumblefoot
• Proper diet
  • Necessary nutrients to fight infection

• Score 1
  • Hyperkeratosis and hyperplasia strictly on the epidermis
  • Moderate hypertrophy of the plantar skin
  • No dark color, but elongated reticulate scales.
  • Erythema
• Score 2
  • Severe hyperkeratosis
  • Superficial dermal congestion and edema
  • Pronounced hypertrophic and hyperkeratotic scales
  • Presence of ulceration
• Score 3
  • Superficial lesions
  • Epithelial necrosis
  • Dark-colored necrosis of (elongated) reticulate scales
• Score 4
  • Dermis abscess
  • Signs of hemorrhages
  • Destruction of the keratin and epidermal layer in the center of the lesion
  • Necrotic tissue exposed

What happens if Bumblefoot is not treated?​

• Very rare for the infection to disappear
  • Proceeds through Scores over a period of a couple of weeks
• The infection spreads to bones, joints, and tendons
  • Causes pain and death
  • The bird may have trouble walking and getting access to food or water
    • Shows weakness to flock
      • Other birds may pick on an injured bird

Is there a need for surgery?​

• `Don't perform- instead clean and aid
  • The wound is only red and has a shiny patch. (Signs of score 1 or moderate score 2
  • Not a lot of swelling, no signs of foreign objects (such as a splinter), no abnormal coloring or growth.
    • Soak in warm Epsom salts to loosen the skin and reduce swelling
    • Apply a triple antibiotic ointment, place a non-stick sterile gauze, and wrap with Vetrap
    • Check wound every 24-48 hours to reapply ointment and assess the wound
      • Should draw the swelling to a head so that the abscess can rupture.
        • Once burst, clean the wound with Epsom salt, re-apply ointment, and re-wrap.
          • The bird is at most risk of a secondary infection!!! Keep as clean as possible!!
          • The wound should heal within 10-15 days.
• Perform
  • Severe Score 2 or above
  • Dark brown or black scab
    • Some call this "the plug"
      • Extremely hard and rough at the touch
      • Necrotizing foot tissue underlying the abscess

Who performs the surgery?​

• (Recommended) Surgery treated by a professional veterinarian that specializes in poultry or avian science
  • The procedure can take up to an hour
• (Not recommended) you can perform the surgery
  • Increase the risk of secondary infection if not qualified professional
    • Injure bird- cut too deep into the wound
    • Careless supplies/procedure

Materials for surgery:​

• Sterile scalpel and tweezers
  • Sterilize with a lighter
    • Ensure no bacteria
• Warm water filled with Epsom salt
• Towels
• Disposable gloves
  • Do not contaminate bird
• Vetrap
  • Wrap wound
• Non-stick gauze pads
  • Aid in dressing wound
• Chlorhexidine 2% solution
  • Or Iodine
    • Kills off bacteria
• Triple antibiotic ointment
  • Prevent and treat skin infections

How to perform the surgery:​

• Soak with Epsom salts
  • Loosen/soften up the skin and get rid of dirt
  • Gently rub the infected area
• Spray Chlorhexidine 2% solution
  • Kill any remaining bacteria
• Wrap bird with a towel
  • Cover head and eyes to prevent flight response
  • Secure bird
• Locate the heart of the abscess
  • Identify: dehydrated pus that has solidified
    • Healthy skin tissue: soft, pliable, and pink
• Surgical Debridement (surgery portion)
  • Use a scalpel to cut around the circumference of the abscess straight down into the foot
  • Tweezers used to remove dead/infected tissue
  • Make sure to sterilize tweezers and scalpel
• Re-soak foot
  • Cleanse
  • Ensure all infected tissue and foreign objects are removed
  • Throughout the procedure, you may have to re-soak the bird's foot in order to ensure the skin is loose/soft.
• Bandaging
  • Chlorhexidine spray
  • Triple antibiotic ointment applied to wound
  • Non-stick gauze placed over the wound
    • Ensure antibiotics remain on foot
    • Creates pressure to stop bleeding
  • Gauze kept in place with vet wrap
• Remove and re-applying bandage every 24-48 hours to assess wound and healing progress
  • If swelling, foul odor, or red streaks
    • Secondary infection- need antibiotic treatment
  • After 2 weeks- fully healed

Vocabulary:​

• ​

  Abscess
  • Pus that has filled up within the dermal layer of the skin
• Ammonia
  • Colorless gas
  • Exposure to skin
    • Produce irritation
• Dermal
  • The thickest part of the skin
  • Lays beneath the epidermis
• Epidermis
  • The surface layer of the skin
    • Overlying the dermal layer
• Epithelial
  • Structure within the epidermis
  • Type of tissue composing the skin
    • A thin, protective layer of cells
• Erythema
  • Superficial reddening of the skin
• Fibrosis
  • Fibrotic connective tissue replaces normal skin tissue in response to disease or injury
    • This leads to tissue remodeling and the formation of permanent scar tissue
• Hemorrhages
  • Ruptured blood vessels
• Hyperkeratosis
  • Keratinocytes undergoing apoptosis (programmed cell death) to produce keratin, resulting in a thickened layer of underdeveloped keratin
• Hyperplasia
  • Increase in the number of cells
• Hypertrophy
  • Increase cell size
• Keratin
  • Fibrous, structural protein
  • Key structure making scales (especially on the scales of poultry feet)
• Lesions
  • Tissue (in this case skin) that has suffered damage through injury or disease
• Microenvironment
  • Small scale environment of an organism or part of an organism
• Necrosis
  • Death of cells (and tissue) due to disease or injury
• Necrotic tissue
  • Dead tissue
• pH
  • The measure of how acidic or basic a substance is
  • The normal pH of chicken skin is between 5-6
    • A pH above or below this causes irritation
      • A pH above 9 may dry out the chickens' skin, causing further irritation
• Ulceration
  • Break of skin; caused by surface cells dying
  • Form of a lesion