A Retrospective Study on Histopathological and Cytological Evaluations to Guide Surgical and Chemotherapeutic Strategies in Canine Tumours

Abstract

Introduction: Canine tumors cause significant morbidity and mortality, yet diagnostic methods in resource-limited settings remain inadequate. The present study assessed the pathological range and compared fine-needle aspiration cytology (FNAC) with histopathology to guide surgical and chemotherapeutic strategies in Veterinary Teaching Hospitals in Ibadan, Nigeria.
Materials and methods: This retrospective study on suspected canine tumour cases (n=73) was collected from 2018 to 2025 across three veterinary centers in Ibadan, Nigeria. Clinical records were reviewed and data on demographics, tumour types, and diagnostic methods were systematically tabulated. Chi-square goodness-of-fit tests were employed to evaluate differences in age groups (middle-aged to geriatric), sex, diagnostic procedures such as FNAC and tissue biopsy, treatment modalities including surgical excision versus chemotherapy, and survival outcomes. Performance metrics of aspiration biopsy, comprising sensitivity, specificity, and predictive values, were calculated in comparison with histopathological findings. Furthermore, McNemar’s test was used to evaluate discordance between fine-needle cytology and biopsy results.
Results: Age distribution was uneven, with the highest prevalence in 5-8-year-olds (30.1%). Male number was dominant (60.3%), but this difference was not statistically significant. Boerboels (37.0%) and German shepherds (30.1%) were more present than other breeds, suggesting possible breeder bias or increased breed-related tumor development. Tumor types included transmissible venereal tumors (21.9%), mammary tumors (13.7%), and lymphomas (9.6%). Use of diagnostic tools was different, with fine-needle cytology accounting for 45.2% and biopsy for 47.9% of procedures. Fine needle cytology had a sensitivity of 85% and specificity of 90%, with a positive predictive value of 92% and a negative predictive value of 81%, showing a nonsignificant difference with histopathology. Treatment approaches were different, with 61.6% receiving chemotherapy alone, 13.7% receiving both chemotherapy and surgery, 5.5% undergoing surgery only, and 19.2% receiving no treatment. The overall survival rate was 38.4%.
Conclusions: The FNAC offered valuable initial information, whereas histopathology provides the definitive diagnosis. Implementing a stepwise diagnostic approach can facilitate more efficient utilization of limited resources, improve accuracy in prognostication, and ultimately enhance survival rates of dogs in Nigeria.