Your dog had blood drawn at the wellness visit. A few days later the clinic emails the results, or hands you the printout at checkout, and it's thirty acronyms, twelve reference ranges, a column of numbers, and two or three little arrows pointing up or down. The receptionist said the DVM would call if anything was concerning. The DVM hasn't called. You still can't read the page.
This is the page the clinic almost never has time to walk through with you, and the page that, walked through once, makes every future panel easier to read. The bloodwork is asking two big questions of two different systems. The CBC, the complete blood count, asks how the blood itself is doing: are there enough red cells, are the white cells in a normal pattern, are the platelets in range. The chemistry panel asks how the organs that the blood serves are doing: liver, kidneys, pancreas, electrolyte balance, blood sugar. Everything else on the page is a finer version of one of those two questions.
The CBC: red cells, white cells, platelets
The CBC is the cell-count test. It tells you how many of each kind of cell is in the blood and what those cells look like. The Merck Veterinary Manual, the reference textbook clinicians use, treats the CBC as the first filter for anemia, infection, inflammation, and clotting trouble. Every chemistry abnormality gets read against the CBC context.
On the red side: HCT (hematocrit) and HGB (hemoglobin) are the headline numbers. Both go down when the dog is anemic, whether from blood loss, immune-mediated destruction, kidney disease, or chronic illness. MCV (mean cell volume) and MCH (mean cell hemoglobin) describe the cells' size and color. A low HCT with a high MCV and a high reticulocyte count is regenerative anemia, the marrow making new cells in response to the loss. A low HCT with a normal MCV and a low reticulocyte count is non-regenerative, which is a different and usually slower-developing problem.
On the white side: WBC is the total count, but the differential, the breakdown of neutrophils, lymphocytes, monocytes, eosinophils, and basophils, is what actually tells the story. A high neutrophil count with low lymphocytes is a stress leukogram or an acute infection, depending on the rest of the picture. Elevated eosinophils suggest parasites or an allergic process. Elevated lymphocytes can mean chronic stimulation or, in older dogs, lymphoma worth watching. None of these patterns is diagnostic alone. They're flags the DVM reads against the exam.
Platelets matter for clotting. A low platelet count, thrombocytopenia, can be lab artifact from clumping during the draw, in which case the lab will note it on the report. A real low can mean autoimmune destruction, tick-borne disease in endemic regions, or bone marrow trouble. The lab almost always recommends a manual smear review when platelets are flagged, because the count from the analyzer is unreliable when the cells are clumping.
Liver values: ALT, ALP, AST, GGT, bilirubin
The liver values are where most owner anxiety lives, and where the per-enzyme nuance matters most. ALT, alanine aminotransferase, is the most liver-specific enzyme on a canine panel. It rises when liver cells are damaged. Causes run from the genuinely uninteresting (recent exercise, a fatty meal, mild trauma) through common and manageable (a medication side effect, a resolving GI bug) to genuinely serious (chronic hepatitis, toxin exposure, hepatic neoplasia). The number on the page is the same in all of those scenarios. The pattern over time and the rest of the panel distinguish them. The dedicated walk-through on what ALT means on dog bloodwork goes deeper on this single value.
ALP, alkaline phosphatase, rises for a broader list of reasons than ALT does. Cholestasis (impaired bile flow), steroid exposure (including endogenous steroid from Cushing's disease), and bone turnover in young growing dogs all raise ALP. On Plumb's 10th edition, the veterinary drug handbook most US vets keep on their desk, isolated ALP elevation is usually less worrying than isolated ALT elevation. The two together, both up, is the pattern that often gets the clinic to add a bile acid test as the next step.
AST, aspartate aminotransferase, and GGT, gamma-glutamyl transferase, are the supporting cast. AST shows up in muscle as well as liver, so an isolated AST elevation with normal ALT often points to muscle, not liver. GGT rises in cholestasis and tends to track with ALP. Total bilirubin elevation, with or without visible jaundice, shifts the conversation immediately into bile flow or red cell destruction, and usually a bile acid test or abdominal imaging follows in the same week.
Kidney values: BUN, creatinine, SDMA, urine specific gravity
The kidney panel is read as a cluster, not a single number. BUN, blood urea nitrogen, tracks how the kidneys are clearing waste, but it's also influenced by diet, dehydration, and GI bleeding, which makes it a noisier signal than creatinine. Creatinine is the kidney number most DVMs watch over time, because it's less diet-sensitive and tracks renal function more directly. SDMA, the newer marker IDEXX introduced commercially in 2015, rises earlier in chronic kidney disease than creatinine does, and the International Renal Interest Society incorporated SDMA into the CKD staging guidelines for exactly that reason.
None of those three numbers means much without the urine. Urine specific gravity is the simple bedside test that tells the DVM whether the kidneys are concentrating normally. A dog with rising creatinine and SDMA but well-concentrated urine is a different clinical picture than a dog with the same chemistry values and dilute urine that can't be concentrated. The chemistry panel alone undercounts early kidney disease, which is why a urine sample at the senior wellness visit is worth asking about even if the chemistry looks fine.
Electrolytes, glucose, protein
Sodium, potassium, and chloride read hydration and acid-base status. Most healthy dogs run inside the reference range; values that drift outside it usually pair with a clinical sign (vomiting, dehydration, an endocrine condition like Addison's disease) that the DVM is already reading on the exam.
Glucose on a fasted draw is mostly checking for diabetes. An elevated glucose on a non-fasted draw, or in a stressy patient, is harder to interpret, and the standard follow-up is a fasted recheck or a fructosamine test that averages glucose over the past two to three weeks. Low glucose, hypoglycemia, on a healthy-looking dog is usually sample handling. On a clinically unwell dog, it's an emergency.
Total protein, albumin, and globulin split the protein number into its two main fractions. Albumin is made by the liver and lost through the kidneys or the gut. Globulin is the immune-system fraction and rises with chronic infection or inflammation. The Merck Veterinary Manual is explicit that the ratio of albumin to globulin is often more diagnostic than either number alone. Low albumin with high globulin points toward chronic immune-stimulation disease. Both low together points toward GI loss or severe blood loss.
Reading a single panel versus reading a trend
A single panel is a snapshot. A trend is the story. The most useful thing an owner can do with a printout is hold onto it, save it in a system where the next year's panel will land alongside it, and bring both to the next wellness visit. The American Veterinary Medical Association's preventive-care recommendations, which most general-practice clinics follow in some version, converge on annual bloodwork through middle age and semiannual once a dog is senior, partly so that the year-over-year trend is even available to read.
Cornell's College of Veterinary Medicine and most US vet schools have owner-facing material that says roughly the same thing: a number inside the reference range that has drifted thirty percent in twelve months is more interesting than a number outside the reference range that has been stable for three years. The trend catches the early version of a problem. The single panel almost never does.
What to keep alongside the printout
The four things that make a bloodwork printout actually useful at the next visit: the printout itself, the current medication list with exact doses and start dates, any notes on appetite or water intake or stool changes in the two weeks before and after the draw, and the prior printout from the same lab if you have it. If the household keeps records scattered across a shared email, an envelope in a drawer, and a photo of a prescription bottle on somebody's phone, that's the starting point most families bring to the pet health records conversation. A timeline of panels, not a single snapshot, is what makes a value like ALT or creatinine actually interpretable, which is the same point the senior pet math piece makes at length.
Questions that come up at the recheck
What is a CBC versus a chemistry panel?
Two different tests, usually run together. The CBC, the complete blood count, looks at the cells in the blood: red cells, white cells, platelets. It reads anemia from the red side and infection or inflammation from the white side. The chemistry panel measures dissolved substances in the blood plasma: enzymes, proteins, electrolytes, glucose, kidney and liver markers. The CBC tells you about the blood itself. The chemistry tells you how the organs that the blood serves are doing. Most wellness draws and most workups include both.
Why are reference ranges different between labs?
Every lab calibrates its own analyzers, and the reference interval on a printout is the band that lab's machine considers normal for its patient population. A reference range from a clinic that runs an in-house chemistry analyzer often reads differently from a reference lab like IDEXX or Antech, even on the same dog drawn the same week. The Merck Veterinary Manual covers this directly: the comparison that actually matters is your dog's value against the reference range printed next to it on that sheet, plus the trend over time at the same lab.
What does a flagged value with an asterisk or arrow actually mean?
It means the result fell outside that lab's reference interval. It does not mean the result is clinically meaningful. A mildly flagged value on an otherwise healthy dog with an unremarkable exam is, statistically, what reference intervals are designed to do. Roughly five percent of healthy patients will land outside any given reference range by definition. Your DVM reads the flag in the context of the rest of the panel, the physical exam, your dog's history, and any prior panels for trend.
Should I worry if one liver enzyme is up but the kidney values are normal?
Often, no. ALT and ALP rise for a wide list of reasons that have nothing to do with serious liver disease, including recent medications, a fatty meal, mild stress, and lab artifact. A single mildly elevated liver enzyme on an otherwise normal panel is a flag for recheck, not a diagnosis. If kidney values, glucose, electrolytes, and the CBC all look reasonable, the workup almost always starts with a repeat panel in two to four weeks rather than imaging or specialist referral.
What is SDMA and why is it on my dog's panel now when it wasn't five years ago?
SDMA, symmetric dimethylarginine, is a kidney marker IDEXX introduced commercially in 2015. It rises earlier in chronic kidney disease than creatinine does, which is why the International Renal Interest Society incorporated it into the CKD staging guidelines. SDMA is also less affected by lean muscle mass than creatinine, which makes it useful in older or thinner dogs where creatinine can read falsely reassuring. If your panel includes SDMA and your DVM is talking about it, they're using a newer tool to catch kidney decline earlier than the old markers alone could.
Can stress at the vet visit change the numbers?
Some of them. Glucose can rise transiently from the catecholamine release of restraint, especially in cats but sometimes in dogs. White cell counts can shift in a stress pattern, with elevated neutrophils and lower lymphocytes, that resolves on recheck. Cortisol, when measured, reads higher under stress. Most of the chemistry panel is fairly stable under stress. The CBC's stress leukogram is the pattern your DVM is checking when a white cell change doesn't quite fit an infection picture.
What does it mean if my dog's albumin is low?
Low albumin, hypoalbuminemia, has three main families of causes: the liver isn't making enough of it, the kidneys are losing it into the urine, or the GI tract is losing it through inflammation. The Merck Veterinary Manual lays out the pattern reading directly. Low albumin alongside elevated liver enzymes points toward liver synthesis trouble. Low albumin alongside high urine protein points toward kidney loss. Low albumin alongside chronic diarrhea or weight loss points toward GI. Your DVM is reading the cluster, not the single number.
How often should my healthy dog get bloodwork?
AVMA's preventive-care recommendations and most general-practice protocols converge on the same shape: annual bloodwork through middle age, then semiannual once a dog reaches senior years (around seven for medium-sized breeds, earlier for giant breeds, later for toys). The senior-pet visit is where the most useful longitudinal bloodwork happens, because year-over-year comparison at the same lab catches drift that a single panel never could. If your dog is on a chronic medication like phenobarbital, an NSAID, or a steroid, the recheck cadence is set by the drug, not by age.
Read the page once, read the trend forever
A panel is a snapshot of two systems on one morning. Read on its own, almost every line is ambiguous: a flag could mean a hundred things, a normal value could miss the early version of a problem. Read against the prior panel and the next one, almost every line becomes a signal. The clinic is reading the trend when the DVM pulls up last year's panel during the recheck. Most families don't have a way to do the same. The fix is small: keep every panel, keep it in one place, and bring it back next year. Call the clinic and ask what they want at the recheck, and bring the home log.
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Rachel Howland, CVT (ret.), spent a decade in clinic: seven years in a mixed practice in upstate New York, then three on the internal-medicine floor at Angell Animal Medical Center in Boston. She left practice in 2017 and has written about small-animal health since. She does not diagnose or prescribe; she explains what your vet's records are telling you and what questions are fair to ask.