Survey of the Clinical, Cytological, and Histopathological Features Associated with Neoplasms in Captive Avian Species in Melbourne, Australia

Abstract

Over a 3.5-year period, tissue samples from 141 companion and aviary birds with clinically suspected, naturally occurring solid neoplasms were collected via surgical biopsy (n = 53) or at necropsy examination (n = 88) from a population of birds presenting to an avian veterinary clinic in Melbourne, Australia. Neoplastic processes were identified in 73.7% (n = 104) of samples, with 83.7% (n = 87) being interpreted as malignant neoplasia and 16.3% (n = 17) being interpreted as benign neoplasia. The overall estimated prevalence of neoplasia in the study population (n = 5125) was 2.45% (95% confidence interval, 2–2.97%). The gastrointestinal and reproductive tracts were the most commonly affected systems. The most common presenting signs were nonspecific and included lethargy, coelomic distension, and inappetence. In 59 cases, fine-needle aspirates (FNAs) and impression smears were also obtained and evaluated cytologically. The accuracy of cytology for detecting neoplasia in birds and for determining whether a neoplastic process was benign or malignant was assessed by using histopathology as the “gold standard.” There was complete agreement between the cytological and histopathological diagnoses in 72.8% (43/59) of cases. Cytology correctly identified 87.5% of these cases (35/40) as malignant neoplasms and 55.6% (5/9) as benign processes. There was no significant difference between the use of cytology and histopathology for the detection of malignant neoplasia in birds (P = 0.185). The accuracies of FNAs and impression smears for examining avian tumors were also compared. Overall, the best cell preservation was obtained by performing impression smears from tissues, with 62.2% (n = 28) returning high cellularity for cytological examination, compared to 53.8% (n = 14) when samples were obtained by FNA. This study provides an overview of the types and prevalence of neoplasms in a captive bird population from Australia, correlates physical examination findings with tumor types, and provides evidence that cytology is a reliable preliminary diagnostic tool for detecting neoplasia in birds.

Myxoid leiomyosarcoma of the oviduct and uterus in a Cockatiel (Nymphicus hollandicus)

“…Previous investigations have shown varying rates of neoplastic involvement in different organs and systems. A study of 141 solid neoplastic lesions of pet and aviary birds revealed higher incidences of neoplasms in the gastrointestinal and reproductive systems (Sutherland et al., 2023 ). In a pathological study of 827 tissue samples obtained from various avian species, neoplasia was diagnosed in 9.2% of birds, with the majority (79%) being diagnosed as malignancy.…”

“…Coeliotomy and surgical excision are accepted as routine treatments for intracoelomic neoplasms (Filippich, 2004 ). Various neoplasms have been diagnosed in pet and aviary birds affecting different organ systems (Nemeth et al., 2016 ; Robat et al., 2017 ; Sutherland et al., 2023 ). Leiomyosarcoma (LMS) is a malignant neoplasm of smooth muscle origin and is the most common sarcoma affecting the uterine tissue in humans (Verta et al., 2023 ).…”