Senior Cat Bloodwork Explained: What the Panel Is Looking For
A senior cat blood and urine panel screens for kidney disease, thyroid trouble and diabetes before symptoms show. Here is what each part is actually testing.
A senior cat panel is a screening test, not a diagnosis — it exists to catch kidney disease, hyperthyroidism, diabetes and anemia while the cat still looks well. Most older cats who turn out to have one of those looked completely normal at home the week before the sample was taken. That is not a failure of observation; it is what cats do.
This article explains what the panel covers so the conversation with your vet is easier. It does not replace a veterinarian, and no number here should be interpreted at home.
What a typical senior panel includes
| Component | What it measures | What an abnormal result may point toward |
|---|---|---|
| Complete blood count | Red cells, white cells, platelets | Anemia, infection, inflammation, marrow problems |
| Kidney values | Waste products the kidneys clear | Chronic kidney disease, dehydration, urinary obstruction |
| Liver values | Liver enzymes and function markers | Liver disease, gallbladder issues, secondary illness |
| Blood glucose | Sugar in the blood | Diabetes — though stress alone can raise it in cats |
| Thyroid hormone | Circulating thyroid hormone level | Hyperthyroidism, very common in older cats |
| Electrolytes | Sodium, potassium and related salts | Dehydration, kidney disease, other imbalances |
| Urinalysis | Concentration, protein, glucose, sediment | Early kidney disease, infection, crystals, diabetes |
| Blood pressure | Not blood, but usually done alongside | Hypertension, often secondary to kidney or thyroid disease |
Practices bundle these differently and use different names. Ask what is included before you agree to a panel, and ask what is not.
Why the urine sample matters so much
Kidneys lose a substantial amount of function before the classic blood values start rising. Urine tells you earlier. A cat whose urine has become dilute is giving you a signal well before the blood does, which is exactly why vets push for both and why a urine sample is worth the inconvenience of collecting one.
If your practice asks you to collect at home, they will usually supply non-absorbent litter and a container. A sample stays useful for a limited time, so ask how quickly they need it. Do not send a sample scooped from ordinary clumping litter — it is contaminated and the result will mislead.
The three conditions this catches most often
Chronic kidney disease. Common in older cats and gradual. Early cases are found on screening, not by symptoms. More detail in chronic kidney disease in cats.
Hyperthyroidism. An overactive thyroid speeds everything up. The classic picture is an older cat eating well but losing weight, often more vocal and more active than usual. See hyperthyroidism in cats.
Diabetes. Increased thirst and urination, often with weight loss despite appetite. A raised glucose alone is not a diagnosis in cats, because stress at the clinic can raise it, which is why vets follow up with other tests before committing.
Note how much those overlap. Drinking more, urinating more, and losing weight sit on all three lists, which is precisely why the answer is a panel rather than a guess.
Reading results without panicking
Three things worth knowing before the results email arrives:
- A flagged value is not a diagnosis. Labs flag anything outside a reference range built from a general population, and mild deviations are common and often meaningless.
- Trends beat snapshots. A value climbing steadily inside the normal range can matter more than a single number just outside it. This is the argument for testing before your cat is unwell.
- Stress skews cats specifically. Glucose and some white cell values can rise from the car journey alone. A good vet reads the result in the context of the exam, not on its own.
Ask for a copy of the results and keep them. If you ever move practice or end up at an emergency clinic at midnight, a two-year history is genuinely useful.
What it costs and how to plan for it
Prices vary widely by region, by clinic, and by how comprehensive the panel is. In-house results in an hour generally cost more than an external lab with a two-day turnaround. Blood pressure, urine culture and imaging are usually separate line items rather than part of the panel.
Ask for the estimate before the appointment rather than at the desk afterwards, and ask whether the practice offers a senior screening package, which is often cheaper than the same tests ordered individually. If you are mapping the whole year, see budgeting for a senior cat.
What to do next
If your cat is over ten and has never had a panel, book one while they are well. A baseline taken from a healthy cat is worth far more than a first-ever test run in a crisis, and it makes every future result easier to interpret.
Frequently asked questions
Does my cat need to fast before bloodwork?
Often yes, usually for several hours, because a recent meal can affect some results. Your practice will tell you what they need for the specific panel they are running, and you should always ask rather than assume, since fasting an unwell or diabetic cat needs different handling.
Why does the vet want a urine sample as well as blood?
Because blood alone can miss early kidney disease. Urine concentration tells the vet how well the kidneys are still doing their job, and a urine sample also picks up infection, crystals, protein loss and glucose. A panel without urine is only half the picture.
My cat's results came back normal. Was the test pointless?
No. A normal result at a known age is the baseline every future test gets compared against, and a value drifting within the normal range over three years can be more informative than a single flagged number. Screening is about trends as much as thresholds.
How often should a senior cat have bloodwork?
Commonly once or twice a year for a well senior cat, and more often for one on medication or with a diagnosed condition. The interval belongs to your vet, who is balancing your cat's age, results history and stress tolerance for visits.
Sources
- Cornell Feline Health Center — Cornell University College of Veterinary Medicine
Found this useful?
Add MyPetGuid as a preferred source on Google and our guides show up more often in your Search results and AI Overviews.