Retrospective Survey of Canine Neoplasm in the National Taiwan University Veterinary Hospital: 1999-2003

Cancer has become the major cause of companion animal death in recent years. Not only used to investigate possible risk factor and environmental exposure, cancer epidemiological study of the pet dogs with spontaneously developing cancer had also provided an excellent opportunity to study many aspects of human cancer from etiology to treatment. The urgency and demand of canine neoplasm survey was required in order to compare the impact of cancer for canine population in Taiwan. A retrospective hospital-based study was performed using data retrieved from medical records for the period January 1, 1999 to December 31, 2003 in the National Taiwan University Veterinary Hospital (NTUVH). The aims of this study were to acquire canine cancer prevalence, distribution and frequency of tumor sites and types, and background signalment information of neoplasm cases from the total hospital population. A total 687 neoplasm cases was obtained and analyzed. The overall prevalence rate of canine neoplasm in NTUVH for the 5-year period was 3.7%, among which 60% were malignant. The high prevalence of neoplasm developed in mammary gland and skin/subcutaneous tissue was observed which comprised 66% of all cases, followed by hematopoietic, urogenital, and oropharyngeal tumors. In terms of tissue of origin, epithelial tumors were more common than mesenchymal and hematopoietic tumors. The ten most prevalent canine neoplasm observed were presented in the order of mammary gland tumor, lymphoma, perianal gland tumor, oral tumor, soft tissue sarcoma, testicular tumor, cutaneous mast cell tumor, lipoma, transmissible venereal tumor, cutaneous squamous cell carcinoma. The results of this survey revealed considerable variation of neoplasm prevalence and breed distribution in Taiwan when compared with other areas. The ultimate goal of this study is to establish a database of canine cancer in Taiwan and investigate potential risk factors by statistical analysis.