What your vet's wellness blood panel tests (and why the results are worth keeping)

What is a complete blood count (CBC)?

The CBC is the count and character of the cells circulating in your pet's blood. It gives your vet a snapshot of three major cell populations:

• Red blood cells (RBC, hematocrit, hemoglobin): Checks for anemia (too few red cells, or cells that aren't carrying oxygen effectively) and dehydration (which can artificially concentrate values). A low hematocrit can explain lethargy, pale gums, or exercise intolerance. A high value may point to dehydration or a rare condition called polycythemia.
• White blood cells (WBC with differential): The WBC count and the breakdown of cell types — neutrophils, lymphocytes, monocytes, eosinophils, basophils — flag infection, inflammation, immune stress, and in some cases, certain cancers. An elevated neutrophil count often means bacterial infection or significant inflammation. An elevated eosinophil count may point to parasites or allergies.
• Platelets: Small cell fragments responsible for clotting. Low platelet counts (thrombocytopenia) raise the risk of uncontrolled bleeding and can be caused by tick-borne disease, immune conditions, or certain medications.

A CBC alone rarely provides a diagnosis — it narrows the field. Your vet interprets the CBC in the context of your pet's age, breed, and history.

What is a chemistry panel (comprehensive metabolic panel)?

The chemistry panel measures metabolites, enzymes, and proteins dissolved in your pet's blood — essentially, a functional map of the organs that filter, process, and regulate. Here's what each group reveals:

• Kidney function — BUN, creatinine, SDMA: BUN (blood urea nitrogen) and creatinine are filtered by the kidneys; elevated levels suggest the kidneys aren't clearing waste efficiently. SDMA (symmetric dimethylarginine) is a newer, more sensitive marker that can flag early kidney dysfunction before BUN and creatinine rise above the reference range. Together, these three give a clearer picture of kidney health than any single value.
• Liver function — ALT, ALP, bilirubin: ALT (alanine aminotransferase) is released when liver cells are damaged — elevated ALT is one of the earliest signals of liver disease or drug toxicity. ALP (alkaline phosphatase) can reflect liver disease, bone disease, or steroid influence. Elevated bilirubin (the breakdown product of red blood cells) can indicate liver disease, bile duct obstruction, or increased red cell destruction.
• Glucose: Blood sugar. Persistently elevated glucose points toward diabetes mellitus. Low glucose (hypoglycemia) can be seen in toy-breed puppies, insulinoma, and certain systemic illnesses.
• Electrolytes — sodium, potassium, chloride: Electrolyte imbalances affect cardiac rhythm, muscle function, and fluid balance. Low potassium can cause muscle weakness; abnormal sodium ratios can be an early indicator of Addison's disease in dogs.
• Total protein, albumin, globulin: Albumin is produced by the liver and reflects nutritional status and liver function. Low albumin can cause fluid accumulation (edema, ascites). The albumin-to-globulin ratio can signal immune system activity or chronic disease.

Your vet may not run every value every year — the panel varies by age, risk factors, and prior results.

What is a urinalysis, and why is it more than a urine sample?

A urinalysis is a three-part evaluation: a chemical dipstick, a measurement of urine concentration, and a microscopic examination of the sediment. Each component catches different problems:

• Urine specific gravity (USG): Measures how concentrated the urine is — a proxy for how well the kidneys are concentrating waste. A healthy cat should produce very concentrated urine. Dilute urine in an otherwise "normal" blood panel can be an early sign of kidney dysfunction that the blood values haven't yet reflected.
• pH: Acidic or alkaline urine can predispose pets to different types of crystal and stone formation.
• Protein: Protein in urine can signal kidney damage (the filter is leaking), infection, or inflammation.
• Glucose: Glucose in urine usually means blood glucose is high enough to spill into the urine — consistent with diabetes.
• Blood: Can indicate urinary tract infection, bladder stones, trauma, or, less commonly, clotting disorders.
• Crystals: Certain crystal types (struvite, oxalate, urate) point toward different dietary or metabolic causes and inform treatment and prevention.
• Microscopic sediment: Bacteria, white blood cells, red blood cells, and casts in the sediment provide diagnostic detail that the dipstick alone can't capture.

Low specific gravity with high BUN/creatinine is more concerning than high BUN/creatinine alone — the combination tells your vet the kidneys aren't compensating, which changes the urgency of treatment.

What else might the wellness panel include?

Depending on your pet's age, species, and geographic location, your vet may add one or more of the following to the annual screen:

• T4 (total thyroxine — thyroid hormone): Hypothyroidism is common in middle-aged to older dogs and causes weight gain, lethargy, and skin changes. Hyperthyroidism is the most common endocrine disease in older cats and causes weight loss despite a good appetite, elevated heart rate, and vomiting. A T4 level takes seconds to add to the blood draw and catches both conditions early.
• Heartworm antigen test (4Dx panel): The 4Dx tests for heartworm antigen plus three tick-borne diseases — Lyme, Ehrlichia, and Anaplasma — from a single blood sample. It's standard for dogs in most regions of the US and recommended annually regardless of prevention compliance (to catch any breakthrough infections).
• Fecal flotation: A stool sample examined for intestinal parasite eggs — roundworms, hookworms, whipworms, coccidia, giardia. Not detected by a blood draw, but often collected at the same annual visit.

These vary by geographic location and your pet's exposure risk. A dog that hikes frequently in tick-endemic areas may be tested more often; an indoor-only cat may not need annual heartworm testing in all regions.

Why keeping baseline results across years matters more than any single result

This is the part most pet owners don't fully appreciate until it's explained by a vet who's been tracking a patient for a decade.

A creatinine of 1.4 mg/dL in a four-year-old dog falls within the normal reference range. By itself, it means nothing unusual. But if that same dog had a creatinine of 0.8 at age two and 1.1 at age three, the trend tells a completely different story — the kidneys may be declining, well before any value crosses the threshold that triggers a red flag on the lab report.

• Dogs and cats with early kidney disease often have values in the normal range at age 4 but trending upward — a pattern invisible without the prior year's numbers beside this year's.
• The same logic applies to ALT creeping up over three years, albumin drifting down, or a T4 that's low-normal this year but was mid-range last year.
• The TREND is only visible if results are stored year over year — and stored in a way you can access, not locked inside three different clinic portals.

This is why your vet might say "the creatinine is fine, but it's higher than last year." That sentence is only possible if last year's results are available for comparison.

What to do with the results after the visit

Getting the results is step one. Here's what to do with them:

• Ask for a copy of the lab report — not just a verbal summary or a portal notification that says "results are in." Request the actual report with reference ranges and numerical values. Most clinics will email or print it on request.
• Note any flagged values — anything marked H (high) or L (low) or highlighted. Ask your vet to explain what each flagged value means for your specific pet, not just whether it's "bad."
• Ask about the plan — is a recheck recommended? A dietary change? More frequent monitoring? A specialist referral? Make sure you leave with a clear next step for every flagged result.
• Store the report alongside prior years. Give your vet your pet's Voocie address — the lab report emails there automatically and becomes part of the health story. Next year, both panels are in one place for comparison.

Published October 12, 2026. This article is informational — it is not a substitute for veterinary care. Your vet interprets your pet's specific results in the context of their individual health history. Always discuss lab results with your veterinarian.