Understanding Your Pet's Annual Bloodwork

At every adult wellness exam, we recommend a CBC (complete blood count) and a blood chemistry panel. If your pet appears perfectly healthy, you may wonder why this is necessary. The short answer: blood panels detect disease before symptoms appear, which is the only window in which many conditions are inexpensive and straightforward to treat. By the time the kidneys, liver, or thyroid shows clinical signs, the organ has often lost 70% or more of its functional capacity. "Baseline" values in a healthy young animal also create a reference point — if something shifts at age 9, we know what your individual pet's normal was, not just where they fall relative to a population average.

The CBC measures three types of cells: red blood cells (checking for anemia, polycythemia), white blood cells (checking for infection, inflammation, or immune disease), and platelets (checking clotting ability). Abnormalities in any of these can indicate infection, cancer, autoimmune disease, bone marrow problems, or medication side effects long before they are clinically apparent. In my internal medicine practice, some of the most important diagnoses I have made started with an incidental CBC finding during a routine wellness visit.

The chemistry panel measures organ function: BUN and creatinine for kidney filtration; ALT, AST, and alkaline phosphatase for liver health; glucose for diabetes; total protein and albumin for nutritional and liver status; electrolytes (sodium, potassium, chloride) for metabolic balance; and sometimes thyroid levels (T4) in cats over 7. Think of it as a systems dashboard. Each value is a data point, and context matters — a mildly elevated ALT in a young dog who just ate a large meal is different from the same value in a 12-year-old dog who has been losing weight. The interpretation always involves the whole picture.

For young, healthy adult pets (1-7 years): annual bloodwork is recommended. For senior pets (over 7): semi-annual bloodwork is the standard of care, particularly in cats. For pets on long-term medications like NSAIDs, phenobarbital, or cyclosporine: bloodwork every 6 months to monitor for medication-related organ stress. If you are ever uncertain about your pet's results, ask us — we review every panel with you at the appointment and are always willing to explain what a value means in plain language. An informed owner is the best partner a pet can have.