A senior blood panel costs $80–180 for the basic version and $120–250 once SDMA and T4 are added, with a urinalysis at $40–90 on top. From age 7 the schedule becomes twice a year, so the real annual number is $240–700 depending on how complete the panel is.
The reason to start at 7 rather than at the first symptom is arithmetic: creatinine leaves its reference range only after roughly two thirds of kidney function is gone, and hyperthyroidism can hide that loss for another 12–24 months by keeping creatinine artificially low.
Why 7 is the line, and why twice a year
Chronic kidney disease (CKD), hyperthyroidism, hypertension and arthritis all become common in the second half of a cat's life, and every one of them is measurable months to years before the cat looks unwell. A 12-month gap in a 13-year-old cat is roughly 8% of that cat's remaining lifespan, which is the argument for 2 visits a year rather than 1.
Twice-yearly testing also builds a trend. One creatinine of 1.9 mg/dL means little on its own; 1.4 rising to 1.6 rising to 1.9 over 18 months means a lot, and the trend is what allows IRIS staging at a point where the cat is still eating normally.
What the $80–180 basic panel contains
The basic panel is a CBC plus a chemistry screen of 15–25 analytes: BUN, creatinine, phosphorus, calcium, glucose, ALT, ALP, GGT, total protein, albumin, globulin, sodium, potassium, chloride, and often cholesterol and bilirubin. Sample volume is 1–3 mL of blood, spun down in 10–20 minutes, and most in-house analyzers return results in 20–40 minutes.
Reference intervals are lab-specific, which is why a creatinine of 1.7 mg/dL can be flagged abnormal by one lab and normal by another. Keep the same lab across visits if you can; comparing 2 labs introduces a 5–15% swing that looks like disease and is not.
Adding SDMA and T4: $120–250
SDMA is a kidney marker that rises at roughly 25–40% loss of function, well before creatinine moves at 66%. It adds $30–50 to the panel and is the single most useful upgrade for a cat over 10. T4 adds $35–60 and screens for hyperthyroidism, which affects a meaningful share of cats past 10 and is treatable at $40–80 a month for methimazole, or cured with radioiodine at $1,200–2,000.
A normal total T4 does not fully exclude hyperthyroidism: roughly 10% of hyperthyroid cats sit inside the reference range on a single draw, so a free T4 by equilibrium dialysis at $45–90 is the next step when the clinical picture fits and the number does not. The reverse trap matters as much: treating hyperthyroidism unmasks CKD in a large share of cats within 3–6 months, because the elevated thyroid hormone had been propping up kidney filtration.
Why the $40–90 urinalysis is not optional
Urine specific gravity (USG) tells you whether the kidney can concentrate, and a dipstick cannot. A cat at 1.060 is concentrating well; a cat stuck at 1.010–1.020 has lost that ability, and that finding can precede any blood change by 6–18 months. The same sample screens for proteinuria, crystals, blood and bacteria, and the sediment exam catches things a strip misses.
Collecting it is the hard part. Non-absorbent litter at $8–15, or a cystocentesis at the clinic which is the cleanest sample and adds $15–40. A sample older than 2–4 hours at room temperature is not worth running, because cells and casts degrade and the USG drifts.
US, UK and China, line by line
| Line item | US (USD) | UK (GBP) | China (CNY) |
|---|---|---|---|
| Basic panel (CBC + chemistry) | 80–180 | 60–130 | 200–450 |
| Panel with SDMA + T4 | 120–250 | 90–180 | 350–650 |
| Urinalysis with USG | 40–90 | 30–65 | 80–200 |
| Blood pressure (Doppler) | 25–45 | 20–40 | 50–120 |
| Free T4 by dialysis | 45–90 | 40–80 | 150–350 |
| Twice-yearly total | 240–700 | 180–520 | 600–1,800 |
Add the exam, and a realistic senior visit lands at $250–350 in the US, £150–260 in the UK and ¥500–1,000 in China, not the $60–90 on the door. Build your own total in the cost calculator, and cross-check the visit rhythm against vet visit frequency and cost by age before deciding between 1 and 2 panels a year.
Why the same panel differs 2x by region and 1.5–3x by city
Region sets the baseline: the identical 15-analyte panel is $80–180 in the US and the equivalent of $90–190 in the UK, but the spread inside one country is larger than the spread between them. A city referral hospital charges 1.5–2x a small-town practice, a 24-hour hospital adds another 1.5–2x, and an out-of-hours slot adds 20–50% on top. That is how the same blood draw reaches $90–100 at a suburban clinic and $260–300 downtown.
What actually drives the line item is whether the panel is run in-house or sent out. In-house results in 20–40 minutes cost $80–180; a reference lab with SDMA and T4 returns in 24–48 hours at $120–250 and is usually the more accurate of the two on low values.
How to prepare the cat, and what to ask for
Fast 8–12 hours for the chemistry, water available the whole time. A cat that ate 2 hours before the draw can show a glucose of 180–250 mg/dL and a lipemic sample that invalidates 3–4 analytes.
Ask for 4 things in writing: the actual values and not just flags, the lab's reference range, the USG as a number, and the previous result side by side. A report that says everything is fine without a USG and without a T4 has not screened an old cat for the 2 conditions most likely to be treatable.
When the numbers mean a vet visit this week
Creatinine above 2.5 mg/dL, phosphorus above 6 mg/dL, potassium under 3.0 mmol/L, or a USG under 1.020 with dilute urine and increased drinking all warrant a call within 24–72 hours rather than at the next scheduled panel. A systolic blood pressure above 160 mmHg on 2 readings needs treatment, because retinal detachment is a $1,500–2,500 problem with a poor visual prognosis and hypertension itself is silent.
At the far end, IRIS stage 4 disease can escalate to hospital care with fluids and dialysis in days; that bill is laid out in transfusion and dialysis cost and runs 5–20x the price of the panel that would have caught the trend 2 years earlier.
4 steps to keep the panel meaningful
- Start at 7, twice a year, and put both dates on the calendar on the same day.
- Insist on SDMA and T4 in the baseline panel once the cat is 10 or older, at $120–250 rather than $80–180.
- Bring a urine sample under 4 hours old, or ask for cystocentesis at $15–40.
- Keep the same lab and file every result; a trend across 3 visits beats any single normal report.
The panel is cheap against what it prevents: $120–250 twice a year against $1,200–2,000 for radioiodine, or a dialysis course priced in thousands. The number to watch is not the invoice, it is the third column of the trend sheet.
Terms mentioned in this article
Frequently asked
Is a basic panel enough for a cat over 10?
It catches anemia, dehydration and advanced kidney disease, but it misses early kidney loss and hyperthyroidism. Adding SDMA at $30-50 and T4 at $35-60 takes the panel from $80-180 to $120-250 and is the difference between staging CKD at IRIS 1 and finding it at IRIS 3, when treatment options are narrower and costlier.
How often should a senior cat be tested?
Twice a year from age 7, which works out to $240-700 a year depending on how complete the panel is. The second visit is not about catching a new disease each time; it is about having 6-month points on a trend line, because a single creatinine value inside the reference range can hide a 40% decline from the cat's own baseline.
Can I skip the urinalysis to save money?
No. Urine specific gravity is the only cheap way to see that concentrating ability is going, and it can change 6-18 months before creatinine moves. A cat at 1.010-1.020 with increased drinking is a kidney case even with perfect bloodwork, and the sample also screens for proteinuria, crystals and infection for $40-90.