Retrospective study of canine cutaneous tumors submitted to a diagnostic pathology laboratory in Northern Portugal (2014-2020)

Abstract

Background

Cutaneous neoplastic diseases are the most and second-most frequently reported tumors in male and female dogs, respectively. The aims of this study were to report the occurrence of canine cutaneous tumors in a pathology laboratory located in Northern Portugal between 2014 and 2020, and to characterize and categorize the anatomical locations, breed, age, and sex of the animals affected with different types of neoplasms. Results

Throughout the 7-year study, 1,185 cases were diagnosed as cutaneous tumors, with 62.9% being classified as benign, and 37.1% as malignant. Mast cell tumors (22.7%) were the most frequently diagnosed tumor type, followed by benign soft tissue tumors (9.7%), sebaceous gland tumors (8.1%), vascular tumors (7.9%) and soft tissue sarcomas (7.6%). Cutaneous tumors commonly exhibited multicentric occurrence (14.6%) followed by single occurrence in hindlimb (12.1%), forelimb (8.6%), buttock (7.1%), abdominal (6.5%) and costal (5.2%) areas. The odds of developing cutaneous neoplasia were higher with increasing age (p < 0.001). Females had an increased odds of developing skin tumors compared to males (crude OR = 2.99, 95% (2.51, 3.55); adj OR = 2.93, 95% (2.46, 3.49). Purebred dogs, as a group, showed a reduced odds of developing cutaneous tumors when compared to mixed-breed dogs (crude OR = 0.63, 95% (0.53, 0.74); adj OR = 0.75, 95% (0.62, 0.89). Conclusions

Mast cell tumors, benign soft tissue tumors and sebaceous tumors were the most common histotypes encountered. The epidemiological survey achieved with this study demonstrates the relative frequency of different types of tumors in this particular population. Furthermore, the results herein achieved can act as a basis or a beneficial reference for local veterinarians helping in the establishment of a preliminary and presumptive diagnosis of canine cutaneous tumors histotypes.