Detailed Clinical and Pathological Characteristics
minor changes in the plantar scales to swelling, fibrous callus or "fibriscess"
the under (plantar) surface of a bird's foot, sometimes with infection extending up
the leg to the hock.
- Initially calluses and hyperplastic tissue on the ball of the foot and/or along the
plantar surfaces of the digits, particularly at the joints.
- Swelling, covered by a hyperkeratotic scab. (B14)
- May become large.
- May become ulcerated.
- May extend into deeper tissue and joints, extending along tendon
sheaths and even reaching the hock joint (B14)
- Deep lesions may become infected.
- Bacterial infection of lesions is particularly common in raptors
- Early changes include erythema and smoothing of the dermal papillae.
Scoring systems have been proposed for bumblefoot lesions
- Type 1: Mild localised lesion, often affecting only one digit,
either proliferative (a raised corn) or degenerative (epithelial
flattening and thinning); in some cases ulceration. The lesion may
progress to form a scab. There may be no infection. (B366.7.w7)
- Type 2: More extensive, pathogenic bacteria are usually involved. An
acute inflammatory lesions with abscessation, but also chronic
reaction such as fibrous tissue and mononuclear cells if examined
histologically. May arise from a type 1 infection, or develop
spontaneously, for example due to the bird piercing its own foot with a
talon, sharp edges of a perch, or infection following entry of a
foreign body such as a thorn. Clinically, the sole (or occasionally a
digit) is swollen, hot and painful, generally with a scab over the
swollen area. Within the swelling may be a clear serous exudate or
caseous pus. Various bacteria may be cultured, often Staphylococcus
aureus; other organisms such as Eschericia coli may be
found as secondary invaders due to faecal contamination. (B366.7.w7)
- Type 3: Chronic condition following from type 2. Infection is walled
off by fibrous tissue, forming one or more pus-filled sacs.
Long-standing cases can result in damage to tendons and infection of
joints, with destructive arthritic changes extending into the shafts
of long bones. (B366.7.w7)
- Type 1: "Enlarged metatarsal pad with infection and
cellulitis of the entire metatarsal pad." (J2.6.w1)
- Trap-induced injuries are in this category. (P7.1.w7)
- The prognosis for these lesions is guarded. (P7.1.w7)
- Type 2: "Enlarged metatarsal pad with a localized
encapsulated lesion." (J2.6.w1)
- The prognosis is fair with surgical treatment (drainage,
irrigation, wound closure once infection is no longer apparent. (P7.1.w7)
- Type 3: "Enlargement of one discrete area of the
- A. "Corns" or other callosites.
- B. Foreign bodies, such as cactus thorn or splinters.
- C. Improper molting of the foot epithelium." (J2.6.w1)
- In the early stages, providing the correct perch, applying a
DMSO preparation and a light bandage is effective for treatment. (P7.1.w7)
- Type 4: "Enlargement of the distal extremities of
the phalanx resulting from rupture of the flexor tendons at the ends
of digits II, III or IV." (J2.6.w1)
- Treatment as for Type 3. (P7.1.w7)
- (J312.4.w1, P7.1.w7)
- Halliwell further commented that the classification he proposed was arbitrary, and that many cases might present as combinations of these
- Swelling on plantar (under) surface of
foot, usually covered with a scab and pus filled.
- Sometimes a large fibrous callus.
- Warm to the touch in acute cases.
- Passive movement of the affected
foot under anaesthesia may be jerky if there is associated tenosynovitis and inflammation of tendon
- Often not infected. (P24.327.w4)
|Early lesions may be seen in
birds such as seabirds after a few weeks in captivity. (P24.327.w4,
Mortality / Morbidity
- It has been suggested that the localised inflammatory response to
infection in birds should properly be considered as a fibriscess,
not an abscess, since rather than tissue necrosis pus formation or
encapsulation, the masses of necrotic tissue are formed of fibrinous
exudate containing the debris of inflammatory cells,, surrounded by a
granulomatous cellular reaction. (J3.147.w3)
- Lesions may be eroded, scabbed or lumpy protuberances.
- Abscesses may extend up to the hock. Infection may progress to give osteomyelitis and bones
of the foot may be eroded. Ankylosis (fusion of the joint) may result.
- Tenosynovitis may result from chronic ulceration and secondary bacterial infection.(P24.335.w14)
- In the lesion associated with fungal infection: granulomatous mass, mainly granulation
tissue, with necrotic fibrous tissue, heterophils and scattered granulomas in the dermis,
totally destroyed epidermis. Fungal elements (hype and yeast's) detected in necrotic outer
dermis, blastosporulated yeasts in granulomas. (J8.26.w1)
may also be seen secondary to chronic infection (B39.w1).
Specific Medical Treatment
treatment depends on the cause of the bumblefoot, the species of bird and
the stage of the condition.
1) Conservative treatment (see below: General Nursing and Surgical
2) Local and systemic medical treatment
- This is appropriate only for relatively superficial infected areas, not for
infection extending into deep structures. (B14)
- A local antibiotic preparation is applied; this may be mixed with
dimethyl sulphoxide (DMSO) to improve penetration into the tissue. (B14)
- 4.0 mg dexamethasone, mixed with 8 oz of DMSO, plus
antibiotic of choice, applied for two to three weeks. (J2.6.w1)
- Systemic antibiotics should be given also. (B14)
- Antibiotic choice should be made based on culture and sensitivity. (J2.6.w1)
- Correction of predisposing factors, such as improvement of substrate
or perches, must be carried out in conjunction with the
- Antibiotics (topical or systemic) may be used together with
appropriate dressings and bandaging in casualty seabirds. (P24.335.w14,
- Cortisone, injected into the lesion, may slow its development; this
should only be used for lesions which are NOT infected. (P24.335.w14)
- Long-acting tetracycline injected into an infected lesion may slow
its development. (P24.335.w14)
- Halliwell (J2.6.w1) Type 3
and 4 lesions:
- Providing the correct perch, applying a DMSO preparation and a
light bandage is effective for treatment. (P7.1.w7)
3) Surgical debridement, long term antimicrobials (choice based on
culture and sensitivity) (B364.10.w10)
- (see below: General Nursing and Surgical Techniques)
It is recommended that, alongside other (medical or surgical)
treatment, Vitamin A
should be given to improve integument health. (B14)
- Small localised infection may respond to local antibiotic preparations (possibly mixed
with dimethyl sulphoxide to improve penetration into tissue), possibly combined with
- N.B. Antibiotics should be chosen on basis of bacterial culture and sensitivity
- Suggested local preparations include Preparation H and a mixture of dimethylsulfoxide
(DMSO) 30ml, dexamethasone (2mg) and chloromycetin succinate (200mg).
- Systemic antibiotics (Ampicillin,
intramuscularly, as a first choice) may be useful in
conjunction with surgery (see below) in more severe cases.
- In the lesion associated with fungal infection, oral ketoconazole: 50mg first day, 75mg
second day, 100mg (12.5mg/kg) third and subsequent days (in association with removal of
main mass of lesion). Total 32 days of drug treatment (J8.26.w1).
Nursing and Surgical Techniques
- Providing the appropriate substrate/perches can, without any other
treatment, lead to resolution of lesions in some cases.
- Resolution following correction of substrate (e.g. a non-abrasive dry substrate)
has been recorded, within a month without other
treatment in some species such as penguins, alcids and shorebirds
and in flamingoes in less than a year. (V.w65)
- Protection of the foot by appropriate bandaging sometimes allows
healing of early lesions in raptors. (B367.w14)
- Flushing of the foot with 1% iodine, a suitable semiocclusive
dressing and bandaging may encourage faster healing. (P24.335.w14)
- This is required for lesions which will not heal with only medical
- For casualty seabirds it is suggested that surgical intervention
should be used "only as a last resort." (P24.335.w14)
- Under anaesthesia, the foot is prepared for aseptic surgery. (B367.w14)
- The scab is removed from the surface of the lesion using toothed
- The surface of the lesion is swabbed to allow bacterial culture and
sensitivity testing. (B367.w14)
- Skin margins around the lesion are examined for vascularity and
- A tourniquet is placed above the tibiotarsal joint to reduce
bleeding; this is released every 15 minutes during the operation. (B14,
- A number 15 scalpel blade is used to make an elliptical skin
incision around the lesion, taking care that the incision is
symmetrical and is perpendicular to the skin surface, and that it does
not extend too deep to involve nerves, large blood vessels or tendons.
- If the lesion involves the metatarsal pad, the incision is made
parallel to the flexure lines on the foot. (B367.w14)
- The tourniquet is released for a moment to ensure that the new
skin margins are properly perfused. (B367.w14)
- Infected and devitalised skin, exudate
tissue are removed. (B367.w14)
and/or serosanguinous exudate is removed, subcutaneous tissues are
curetted until all exudate and necrotic tissue has been removed. (B367.w14)
- A blunt probe is used to explore extensions of infection into
tissue if required. (B367.w14,
- A simple skin incision is made if required to reach pockets of
infection which cannot be reached with the curette from the main
- Following curettage, the area is irrigated thoroughly using
chloramphenicol sodium succinate or potassium penicillin, in
50-100 mL sterile physiological saline. (B367.w14)
- Irrigation with trypsin has also been suggested, to ensure
that all necrotic material is removed. (B366.7.w7)
- Note: Meticulous surgical technique is essential. (B367.w14)
Great care must be taken to avoid nerves, blood vessels and
while removing all necrotic material (B366.7.w7).
- The lesion is then sutured closed. (B367.w14)
- 5-0 monofilament nylon or 6-0 multifilament wire, with an
atraumatic cutting needle is used to suture the skin. (B367.w14)
- In lesions with large skin defects, absorbable subcutaneous
sutures are placed in the subcutaneous fascia in a simple
interrupted fashion. (B367.w14)
- To close the skin, horizontal mattress sutures are placed in the
skin at midthickness to ensure precise apposition of skin edges;
simple interrupted sutures may be placed between the mattress
sutures to give linear apposition of the skin edges. Sutures
should be about 2 mm apart and 2 mm from the edge of the wound. (B367.w14)
- The feet are bandaged to protect the affected area during healing. (B14,
- A nonadherent dressing is placed next to the skin. (B14)
- A padded perch is provided during healing. (B14)
- Systemic antibiotic therapy is given for 7-10 days, preferably
parenteral (intramuscularly), otherwise orally. (B367.w14)
- Antibiotic choice should be made based on culture and
- Sutures may be removed after 10-21 days, depending on healing. This
may be carried out under manual restraint or light anaesthesia,
depending on the bird. (B367.w14)
- Halliwell (J2.6.w1) Type 1
lesions require rigorous surgical treatment and the prognosis for
these lesions is guarded. (P7.1.w7)
- Halliwell (J2.6.w1) Type 2
lesions have a fair prognosis following surgical treatment
(drainage, irrigation, wound closure once infection is no longer
- Encourage to spend more time on water, ensure adequate pool space and that water is easy
to enter and exit, and provide soft surfaces to walk on - natural grass or
butyl rubber matting (B11.36.w4,
- Daily cleaning with iodine scrub followed by camphor spirits as a drying agent and
benzoin to toughen tissues (B13.46.w1).
- Anaesthetise (General Anaesthetic).
- Place tourniquet around lower tibiotarsus to reduce bleeding from granulation tissue
(N.B. release periodically).
- Thorough curettage to remove all caseous and necrotic material.
- Vigorous irrigation of the area, preferably using chymotrypsin solution.
- Suture skin with non-absorbable sutures, mattress sutures.
- Packing of wound with gelfoam and sulfanilamide powder sometimes recommended before
- Post-operative bandage for up to three weeks: bandage foot with non-adhesive dressing
against operation site plus soft dressings.
- Further protection may be provided by attaching foot to foot-shaped piece of stiff card
or plastic using zinc oxide tape, followed by a water-repellent dressing over the whole
- A foot cast may improve healing:
- Cover foot with thin sheet of polyurethane foam (from DIY "Do It Yourself"
- Make cast of foot using Hexcelite, dental acrylic, Technovite or plastic padding. Mould
to plantar under) surface of foot while still soft.
- Hold in position with self-adhesive elastic bandage (e.g. Vetwrap).
- Once fully set, remove cast, cut hole in centre and smooth off edges.
- Replace cast: central metatarsal pad and surgical incision are now free from pressure.
- N.B. regularly inspect foot for swelling and check wound every 2-3 days.
- Improve nutrition and supplement Vitamin
A to improve integument health (B11.36.w4,
- N.B. treatment often unrewarding (B13.46.w1).
and Population Control Measures
|General Environment Changes, Cleaning and
|Ensure appropriate substrates
are provided at all times (P24.335.w21)
- House on appropriate substrate or maintain on water. (P24.335.w20)
- Avoid rough and abrasive surfaces such as concrete or artificial
- Soft substrates should be provided. (B188)
- Smooth (but non-slip), easily cleaned rubber matting is
- Clean dry sand may be used. (P24.335.w21)
- Lawn may be used. (P24.335.w21)
- Net-bottom cages may be used. (B363.9.w9,
Birds of Prey:
- Provide an appropriate environment in which the birds feels secure,
with minimal stress. B367.w14
- Ensure perches are of appropriate design and construction for the
- Ensure landing surfaces for both tethered and free-flying birds are
soft and padded. (B367.w14)
- Regularly examine the feet for early changes such as erythema and
smoothing of the dermal papillae. (B14,
||Avoid rough concrete in enclosures. Cover
concrete e.g. with Astroturf where practical (B14).
Design for Birds - Substrate, Accommodation
Design for Birds - Hospital Accommodation, and Treatment
and Care - Supportive Care & Nursing
|Population Control Measures
|Isolation, Quarantine and Screening