Tumors of the Psittacine Ovary and Oviduct: 37 cases
Presenting Author: Drury Reavill, DVM, Dipl ABVP (Avian)
Pathologist for Zoo/Exotic Pathology Service, West Sacramento
Interpretive Review and comments by Dr. Nemetz:
In clinical practice The BIRD Clinic has seen a great deal of reproductive pathology in female psittacines. But, of the tumors diagnosed, which birds have the highest frequency? What types of cell origin were these tumors? Was the prognosis good or poor? Dr. Reavill's paper aimed to answer these questions.
She found that reproductive tumors are most often described in cockatiels ( Nymphicus hollandicus) and budgerigars ( Melopsittacus undulatus). Even though less frequently reported, reproductive tumors do exist in other psittacine species. At the BIRD Clinic almost every species is represented but after those mentioned by Dr. Reavill, South American species are most often seen with reproductive pathology.
In a review of 37 cases between 1998 and 2003 Dr. Reavill found the following:
Species other than cockatiels and budgerigars: Amazon parrot, parrotlet, macaw, cockatoo, African grey parrot, grey cheeked parakeet, blue-crowned hanging parrot, monk parakeet, and rosella.
The most common ovarian tumors were 1) adenocarcinoma and 2) adenoma. The first neoplasia has a very poor prognosis, but the second benign process with advanced microsurgery has a guarded prognosis if the entire tumor can be removed.
The most common oviductal tumors were the same as ovarian tumors, however they have a better prognosis if diagnosed and removed before metastasis. Dr. Nemetz has had many surgical successes since 1987, but the key is an early diagnosis. Avian patients with oviductal tumors tend to demonstrate earlier symptoms than birds with ovarian tumors.
Of the 37 cases, it was mentioned that the attending veterinarians attempted surgery in 13 of the cases (a macaw with an ovarian leiomyosarcoma was submitted by The BIRD Clinic). Two of the cases showed a partial clinical response of living a short time but of the 13 case, only the case submitted by Dr. Nemetz is still alive 18 months after surgery.
Ovarian and oviductal tumors exist in many of our psittacine species with the majority occurring in cockatiels and budgerigars, perhaps from the extensive breeding pressure on these birds over many years in the pet industry. The key to success is an early diagnosis and a veterinarian's knowledge of avian surgical anatomy and the fine art of microsurgical techniques. If you have one of these conditions diagnosed in your bird, ASK these important questions:
1. What is the long-term prognosis given the specific tumor type?
2. Does the clinic have the proper microsurgical equipment to perform these delicate surgeries?
3. How many of these types of procedures have the veterinarian performed?
4. What has been the success rate of survival from the surgery?
5. What will be an estimated life-span after surgery?
Based on Dr. Nemetz's experience over the years in performing over 200 such surgical procedures he has observed the following:
1. Ovarian neoplasia has a poorer prognosis with most having a long-term prognosis of less than one year; however he has had exceptions extending into several years.
2. Oviductal neoplasia, diagnosed before metastasis, has had a terrific prognosis at The BIRD Clinic with many cases living over 5 years past the surgical procedure.
3. Microsurgical equipment is essential to success. The BIRD Clinic has the finest microsurgical equipment available including a pair of 5X magnification Zeiss headsets. This kind of equipment assisted in the successful removal of a diseased oviduct in a canary with this bird still presently alive over a year after surgery. It wasÂ also used to remove the ovarian neoplasia in the blue and gold macaw presented in Dr. Reavill's paper.