We diagnose cancer by taking a detailed history then physically examining your pet. Blood samples, x-ray and ultrasound are the most common diagnostic aids. MRI and CT scans are enormously beneficial but very costly although recent technological advances are reducing the expense. A sample of suspect tissue is almost always necessary for an accurate diagnosis.
If a sample is taken a small tumour is usually completely removed while for larger ones we may either take a small piece of suspect tissue, a biopsy, or use a needle and syringe to withdraw a sample of cells (a fine needle aspirate) from the tissue, to send to a pathologist.
Many tumours are visible or can be felt on or under the skin, including those in mammary tissue, testicles, lymph nodes or in the mouth. Others are discovered when we carry out routine annual physical examinations. Internal cancers may occur in the spleen and liver, also commonly in the gastrointestinal tract and bladder. Unlike in humans, primary lung cancer is rare in pets although the lungs are a common location for some cancers to spread to. Cancer is more common in older rather than in younger individuals.
The earlier a diagnosis is made the more promising the outcome. This is perhaps the most important reason why cats and dogs should have a yearly preventative veterinary examination.