Osteosarcoma (OSA) in dogs: Clinicopathological evaluation of 21 Cases

Abstract

Osteosarcoma was diagnosed in 21 dogs based on cytological evaluation of FNAC samples collected from tumour-suspected cases, representing an incidence of 0.37% of all canine tumours recorded during the study period. The highest frequency of osteosarcoma-positive cases was associated with lesions of the ulna, followed by the femur, hock joint, and other skeletal sites. Analysis of breed, sex, and age distribution revealed a higher incidence in Rottweilers, Great Danes, and Dobermanns, with a marked predominance in male dogs and in those aged above five years. Cytological examination of the smears demonstrated moderate cellularity with occasional areas showing a lytic bone pattern. The neoplastic cells predominantly occurred as cohesive aggregates embedded in an eosinophilic, bright pink fibrillar osteoid matrix, rather than as individual cells.