Papillomatous Disease In
A Yellow-Collared Macaw
An Article by Gillian Willis
Case Report: Comico, my 13-year-old yellow collared macaw was
diagnosed as having a papilloma near the larynx and another in the
cloaca during a routine health examination. Sixteen months ago, he
underwent cryosurgery (freezing) to destroy these lesions. Since
then, the lesion in the oral cavity recurred and nearly obstructed
the larynx.
Comico recently underwent electrocautery (burning) to destroy this
tissue. Hemorrhage can occur during surgery in the oropharynx. In
Comico, during the second surgery, this was controlled with local
coagulants, but he also required a blood transfusion to replace
blood loss.
Comico made a rapid recovery from both of his surgical procedures
for his laryngeal papillomas and enjoys excellent health.
Fortunately, the cloacal papilloma has not recurred.
Discussion: Papillomatous disease of parrots is believed to be
caused, but not proven to be, by a papillomavirus. No virus has been
isolated. Genetic predisposition may play a role. Once a bird with
papillomatous disease has been introduced to an aviary, other cases
have been observed. Cage mates and offspring of affected birds are
at higher risk of developing the disease.
This disease is most commonly seen in the new world parrots with
Macaws, Amazon parrots, Hawk-headed parrots and Conures being the
usual victims. The papilloma lesion resembles a raised pink or grey
cauliflower-like mass varying in size from microscopic to over 1 cm
in diameter. Papillomas can occur in the oropharynx, choanal cleft,
larynx, esophagus, crop, proventriculus, ventriculus, cloaca,
conjunctiva and tear duct.
Clinical signs of the disease include difficulty in breathing and
straining to defecate. Cloacal papillomas may prolapse, ulcerate and
bleed. Lesions of the digestive tract may cause regurgitation and
weight loss. Some birds with internal papillomatous disease develop
bile and/or pancreatic duct carcinoma which will lead to their
demise.
Autogenous vaccine have been tried to control this disease but the
results have been disappointing. Surgical procedures including
cryosurgery, electrocautery and laser surgery have been used.
Typically, papillomatous lesions wax and wane and may even appear to
regress entirely. Surgery is effective at temporarily eliminating
some aspects of this disease. However, it may not affect the
long-term survival of birds with this disease since recurrence of
the lesion is likely.
In order to control papillomatous disease, a complete veterinary
examination of all newly-acquired birds before introduction into an
aviary may reveal early signs of this disease, Birds should only be
obtained from a reputable breeder. Quarantine periods of 6 months or
more may prevent the introduction of the disease into an aviary.
Clinically affected birds should be removed from the aviary. These
birds my be kept as pets so long as they are not kept with new world
parrots that are at risk for developing papillomatous disease.
Conclusion: Papillomatous disease is not uncommon. Early diagnosis
and treatment may prevent complications. Comico was fortunate in
having his disease detected at an early stage during a routine
health examination. He is monitored closely for recurrence of the
disease and for alterations in blood chemistry. He is on a pelleted
diet supplemented with nuts, fruit, vegetables, vitamins, minerals
and people food. Comico may not live his normal slife span but with
surgery a good diet and lots of TLC, there is no reason why I
cannot enjoy his affections and antics for many years to come.
Copyright © Gillian A.Willis. Permission to re-use any
part of this text (whole or in part) must be obtained from the
author.