As in humans, screening tests for cancer will evolve as new technology is developed and information is acquired to suggest improved outcome or quality of life. Colonoscopy, mammography and tissue specific protein assays (Prostate, Ovarian cancer proteins) have become mainstream screening tools for humans. In companion animals, it is well known that certain breeds are prone to develop cancer. In general, because cancer is a common disorder of older dogs and cats, animals beyond the age of 7 or 8 years of age should be considered ³at risk² for cancer. General screening recommendations such as bi-annual physicals, screening laboratory bloodwork and urinalysis are becoming more common for geriatric animals. In addition, the use of cutaneous maps to chart the location, size and diagnosis of all skin masses will help to determine rapid changes in growth or any new masses to be concerned about.
Owners should be encouraged to take responsibility for prevention of cancer and frequent screening. Early neutering male and female dogs is the best example of cancer prevention. Dogs are now known to develop upper respiratory and lung cancer when exposed to second-hand smoke and should be removed from a passive smoke environment. Observation of bowel or urinary habits should be strongly encouraged. Owners should also be able to accurately evaluate mammary glands, peripheral lymph nodes, oral cavity structures, examine interdigital spaces and external ear canals. Recommendations for more elaborate screening will depend on client concern for early detection, financial considerations and validation of the benefits for early screening.
Recommendations for thoracic radiographs, abdominal ultrasound, colonoscopy and even CT/MR of the nasal cavity and brain may not be too extreme if early diagnosis means improved outcomes for serious forms of cancer.