Clinical Management
The
first step in bumblefoot management is the education of the keeper.
The routine of daily handling, and monitoring of foot health is invaluable.
If cases can be detected at Stage 1, then virtually all will immediately
respond to conservative therapy (ie. finding the cause of the problem, eg.
unsuitable perches, and rectifying this). On presentation of more serious
cases a full history is taken and the bird should receive a full clinical
examination. Any other disease, causing foot problems (eg. pox, frost bite,
spinal or pelvic limb injuries etc.) or general illness (eg. nutritional
deficiencies, aspergillosis, tuberculosis etc.) should be considered. If the
cause is husbandry related, then the lesion is likely to be similar or
identical in severity and location on both feet. Husbandry problems vary from
simply standing for excessive periods on inadequate perches (often smooth and
hard), unsuitable furniture (with the brass eyelets of Aylmeri or bells
repeatedly knocking against and bruising the ankles or feet), to repeated
trauma of hitting or grasping fencing or other materials that have been used
in the construction of the aviary. Alternatively some birds when either flown
to the lure or flown free at quarry, have an unfortunate habit of hitting
quarry (binding to) or lure with excessive force with their feet, leading to
repeated bruising and foot damage. If this occurs when flown at the lure, an
improved lure design, a lighter weight lure, or more careful use of a lure
can help. If the cause is a consequence of a penetration, this may be as a
result of the way the bird is caught in the aviary, possibly it has overlong
talons or due to foreign body (thorn) puncture, or bite wounds from quarry
(squirrels, rats etc.). Bumblefoot never only affects one foot. As soon
as one foot is affected additional weight is born by the good
foot, the latter rapidly suffers with a `pressure necrosis bumblefoot'. If
only one foot appears affected, action should be taken to dissipate weight
over the whole surface of the good foot, including the toes, rather than
simply the ball of the foot, in order to prevent disease of the second foot.
The same applies to any bird with any leg injury (eg. following any leg or
pelvic injury), the other (healthy) leg will be bearing more weight than
usual and should be suitably padded, if this is not done (in falcons in
particular), a bumblefoot will rapidly develop. It is for this reason that
amputation of the leg of a raptor should never be considered, as the
remaining good leg will inevitably develop bumblefoot,
sooner or later. |
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In all cases the first step is to take a swab to
test the bacteria to see what antibiotic is likely to be
effective. In mild cases, foot dressing and antibiotics alone may be
effective, however in more serious cases, (and in those which do not respond
to medication), surgery will be indicated. If at all possible the whole lesion
should be removed in one piece converting a necrotic infected area of tissue
into a clean, surgical site with a good blood supply that may be sutured
closed so that it heals well. Whilst in the past lesions may have been opened
and the infected material scraped out, the author now favours a technique
where the whole infected area is cut out in one clean section. Patients are
routinely anaesthetised using Isoflorane, the foot is disinfected and the
infected material surgically removed. Prior to closure of the wound, three
cavities are created between and about the toes, into each of these cavities
an antibiotic impregnated bone cement bead is placed. These beads will
continue to release antibiotics into the local area surrounding the
previously infected tissue for a period of months. The beads are usually left
in the foot, although they may be removed from the top of the foot, if that
should prove necessary at a later date. Following surgery it is imperative that pressure
is effectively relieved from the operation site (ie the ball of
the foot). In a normal stance the total bird's weight is applied to this
particular area. In recent years a number of different systems have been
developed to achieve this. Differing structures are required for different
species, for small species corn plasters are used, for larger species a
similar shaped dressing made of rigid foam, or a fabricated circular padded
structure. These dressings make contact with the bottom of each toe at its
base where each toe meets the ball of the foot. The end result is that
the ball of the foot does not ‘weight bear’ at all, and
air is free to pass around the healing wound. Dressings are made from rigid foam,
plastic, wood or a circle of wire, amply padded with foam and cotton wool.
Antibiotics are maintained by mouth or injection for 14 21 days. These padded dressings
look cumbersome, but |
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in fact birds appear very comfortable in them,
although their food does need to be cut up, as the bird is unable to pull on
its food whilst wearing these dressings. Conclusion
Bumblefoot
has been a serious affliction of falconers birds for thousands of years. A detailed description was made by Holy Roman
Emperor Frederik II of Hohenstaufen (1194 1250) in his monumental
treatise, De Arte Venandi Cum Avibus.
The earliest reference to surgical treatment of the disease appears in
Falconry, or the Falcons Lure and Cure published in 1615 (Cooper 1980).
However despite its long recognition, the condition remains an all too common
affliction of captive raptors. Full surgical debridement, is still considered
to be essential for successful treatment even when employing the use of bone
cement beads. The correct and full relief of pressure from the ball of the
foot following surgery is essential. Each part of this treatment regime is
essential, however in combination it has been shown to achieve a very high
level of long term cure, which is significantly improved on previously
reported recovery rates. REFERENCES Cooper JE (1980). Surgery of
the foot in falcons : an historic operation. Annals of the Royal College of
Surgeons of England; 62: 445 448. Remple JD, Forbes NA (1998).
AntibioticImpregnated Polymethylmathcrylate Beads in the Treatment of
Bumblefoot in Raptors. In: Raptor Biomedicine II (In Press). Neil A Forbes BVetMed CBiol
MIBiol Dip ECAMS FRCVS European Veterinary Specialist in Avian Medicine and
Surgery RCVS Recognised Specialist Zoo Animal and Wildlife Medicine (Avian)
Clockhouse Veterinary Hospital Wallbridge, Stroud, Glos GL5 3JD ENGLAND |
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INTERNATIONAL FALCONER MAGAZINE |
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Article and pictures courtesy of International
Falconer Magazine |
