Bumblefoot in the Bird.
Bumblefoot aka pododermatitis is a general term for any inflammatory condition of the
avian foot. Causes of Bumblefoot are as follows:
Mild lesions are common with those fed on all seed diets, or those oversupplemented with
fruit and vegetables diets, overweight birds, those not exposed to sunlight.
Bruising and abrasions of the feet may develop especially in birds of prey. Soft tissue injury
involving one leg or foot may cause excessive weight bearing and Bumblefoot. Traumatic
injuries such as bite wounds from prey can lead to the invasion by pathogenic bacteria at
these sites may lead to abcessation, joint changes and osteomyelitis.
Dry flaky hyperkeratic skin on the feet (due to malnutrition, for example) changes the
mechanics of weight bearing on metatarsal pads leading to reduced circulation,
microepithelial damage, localised impairment of the immune system and the consequent
introduction of opportunistic pathogens.
Proper perches, flight pen or cage construction, nutrition, general health of the bird should
be monitored in order to prevent Bumblefoot.
Treatment should aim to reduce inflammation and swelling begins antibacterial if necessary
to eliminate underlying pathogens and establish drainage if needed.
The Anatomy and Physiology of the foot of the Bird.
The Anatomy of the foot , an unfeathered area of the integument and is a common site for
primary skin disease; it includes the shank (metatarsus), spur and 1-4 toes.
The scales on the shanks and feet are keratinised and cornified epidermal patches similar
to those observed in reptiles.The skin consists of the following:
The epidermis of birds consists of three layers:
 The basal layer
 Intermediate layer
 Outer cornified layer
There are striated muscles located in the epidermis to move the skin.
The dermis is divided into superficial and deep layers. The superficial layers contain loosely
arranged layers of collagen that are contained in interwoven bundles. The deep layers
contain the fat, feather follicles , smooth muscle to control the movement of the feathers
and large blood vessels and nerves that supply the dermis and epidermis.
The forward pointing three toes are webbed. The spur on the caudomedial surface of the
metatarsus is used as a weapon. The length of the metatarsus may be used as an age
determining factor. There is a sebaceous oil gland (uropygial gland), which is the only skin
gland present apart from those in the external ear and at the vent (similar to anus in
mammals). The secretion of this gland is carried to the body and wing feathers during
preening. The uropygial gland is prominent in some species and has a water
proofing function.
The Common Clinical Procedures:
Blood sample collection: In birds the circulating blood volume is generally between 6 and 12
ml /100g body weight( 10% of the body weight). Overall birds can tolerate a greater degree
of blood loss in relation to size than can mammals. The suitable locations for blood collection
are the right-sided jugular vein, which unlike mammals, is more mobile and can be found subcutaneously over the right side of the neck. This site cannot be used in pigeons, as there is
an extensive. Place finger under the neck with the birds head extended, the skin can be
tensed over the site and the thumb can be placed in the thoracic inlet to raise the vein.
Urine sample collections: urea forms 20-40%of avian nitrogenous waste and is excreted by
glomerular filtration.In normally hydrated birds a little urea is reabsorbed, whereas in
dehydrated birds, nearly all urea is reabsorbed into the bloodstream. Therefore any factor
such as cardiopathy or dehydration can cause a rapid rise of urea in the plasma.
Common Injection sites: The most common injection site for birds of parenteral
administration of drugs is in the intramuscular region. Either the pectoralis or the
iliotibialis lateralis or biceps femoris muscle can be used. Injections can be given
subcutaneously but only one or two sites are suitable because the avian skin is inelastic and
fluids tend to leak out at point of needle puncture. Injections can be given intravenously and
is most easily given to the brachial vein but can also be given to the tarsal vein on the medial
surface of the leg, as can the right jugular vein.