| The following article is used with the written permission of the author, Gillian Willis, pharmacist and toxicologist. |
Papillomatous Disease In
A Yellow-Collared Macaw
| 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. |
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Gillian Willis |