Seven-Year Follow-Up of Tumors in Young Dogs in the Republic of Serbia

Although the incidence of neoplasms increases with age, some tumors occur more commonly in younger dogs. Still, little information is available on the occurrence of neoplasms in dogs up to the age of 24 months. This study is a retrospective review of histopathological diagnoses of neoplasia at our laboratory during the last seven years (2017–2023) in two groups of dogs: group up to the age of 12 months and group from 13 to 24 months. In a total of 3704 neoplasms found in different dog tissues, 74 (2.00%) were identified in dogs up to 12 months and 135 (3.64%) in dogs aged 13 to 24 months. Canine cutaneous histiocytoma was the most frequent in both groups:41 cases (54.41%) in dogs up to 12 months, followed by 39 cases (28.89%) in those up to 24 months. In the present analysis of the group up to 12 months, 82.43% of tumors (n = 61) were benign, and 17.57% (n=13) were malignant, followed by 68.15% (n=92) benign neoplasms, and 31.85% (n=43) malignant in dogs aged from 13 to 24 months. French bulldogs and mixed-breed dogs were the most frequently affected. These data provide valuable epidemiological information on neoplasms in young dogs in the Republic of Serbia.