Datasets from 849 dogs ≤ 3 years of age were analysed retrospectively, considering breed, sex, anatomic sites, multiplicity, tumour diameter, grading, and immunohistochemistry by using IBM® SPSS Statistics (version 29.0.2.0). Danish–Swedish farm dogs (OR: 8.11, 95% CI 3.33–19.77, p < 0.001) and English Setters (OR: 6.68, 95% CI 3.20–13.97, p < 0.001) showed the highest odds ratios (ORs) compared to crossbreeds. German Shepherd Dogs showed lower ORs (OR: 0.05, 95% CI 0.007–0.364, p < 0.01). The most common sites affected in the young dogs were the trunk (39.2%), hind limbs (24.9%), head (10.1%), fore limbs (7.4%), and pinnae (5%). Patnaik grading revealed 330 grade I (35.7%), 580 grade II (62.8%), and 14 grade III MCTs (1.5%). Kiupel “low grade” was found in 903 MCTs (97%), and 21 MCTs were “high grade” (3%). The prevalence of grade I MCTs was higher in Boxers (48.0%, p < 0.05) and Pugs (67.9%, p < 0.01). Pinnal MCTs were mostly grade I (58.3%, p < 0.01). In 6% (n = 51), multilocalised MCTs were found, and Golden Retrievers (12.5%, p = 0.02) and Pugs (21.4%, p = 0.005) were more affected than crossbreeds. Out of 87 dogs, 20 showed a Ki-67 count above the cut-off as well as KIT staining pattern II. The findings warrant heightened vigilance in evaluating cutaneous lesions in young dogs and highlight similarities and differences compared to the general dog population. Analysis of survival data is required to evaluate how the findings translate into a clinical setting.
Schwinn et al. (Thu,) studied this question.