Age Factors Animals Bites and Stings Blood--microbiology Bone Marrow--microbiology California Dog Diseases--transmission Dogs Epidemiologic Methods Fibrosarcoma--epidemiology Humans Leukemia--veterinary Lymphoma--veterinary Microscopy, Electron Neoplasms, Connective Tissue--epidemiology Saliva--microbiology Sex Factors Urine--microbiology