Canine paediatric oncology: retrospective assessment of 9522 tumours in dogs up to 12 months (1993-2008).

Little information is available on the occurrence of neoplasms in dogs up to the age of 12 months. This is a retrospective review of histopathological diagnoses of neoplasia in dogs up to the age of 12 months based on biopsy specimens submitted to a commercial veterinary diagnostic laboratory in the United Kingdom between 1993 and 2008. In 20 280 histological submissions, 9522 neoplasms were identified. Canine cutaneous histiocytoma (n = 8465; 89%) was the most common histological type. Neoplasms other than histiocytoma (n = 1057; 11%) were grouped as benign epithelial (n = 375; 4%), haematopoietic (n = 229; 2%), benign mesenchymal (n = 145; 2%), miscellaneous (n = 118; 1%), non-hematopoietic malignant mesenchymal (n = 118; 1%) or malignant epithelial tumours (n = 72; <1%). Excluding canine cutaneous histiocytoma, 52% of tumours (n = 547) were benign, and 66% were from the skin or soft tissues. These data provide valuable epidemiological information on neoplasms occurring in juvenile dogs in the United Kingdom.