Building on the success of previous editions, the Editors have sought to marry the best of the old with the new. All chapters have been updated, or rewritten, by international experts to encompass the important advances made over the last several years, while keeping the text practical and user-friendly. The principles of diagnostics and clinical staging and of the main therapeutic modalities are outlined. Individual tumour types in the body systems of dogs and cats are then described, using a common approach to aid information retrieval on aetiology and pathogenesis, presentation and clinical signs (including staging/grading of tumours), management , and prognosis. A wealth of new photographs has been included to illustrate the clinical, diagnostic and therapeutic aspects of a range of tumours. The growing importance of ethical considerations and palliative care are also recognized, and exciting developments and treatment possibilities explored.