Your Dog’s Blood Test Results May Depend on How the Sample Was Stored
When your vet draws blood from your dog for a routine checkup, you probably focus on the results — are the numbers normal? But there’s a step between the needle and the answer that doesn’t get much attention: how the blood sample is stored before it reaches the analyzer.
A new lab study published in Animals found that blood sample storage temperature is linked to how stable — and therefore how reliable — a dog’s complete blood count (CBC) results are. Specifically, different blood cell types fared better under different conditions. This research may help veterinary clinics fine-tune the way they handle samples for quality-testing programs.
What Is a CBC and Why Does It Matter?
A CBC — complete blood count — is one of the most common blood tests vets run. Think of it as a snapshot of everything floating in your dog’s blood. It measures:
- White blood cells (WBCs) — the cells that fight infection
- Red blood cells (RBCs) — the cells that carry oxygen
- Platelets — the tiny cells that help blood clot
These numbers help vets spot infections, anemia, inflammation, clotting problems, and dozens of other conditions. A reliable CBC can be the difference between catching a problem early and missing it.
But for the numbers to be trustworthy, the blood sample has to be in good shape when it reaches the analyzer. That’s where storage comes in.
Why Storage Conditions Are Worth Studying
Veterinary clinics increasingly use point-of-care CBC machines — analyzers right in the exam room — rather than sending blood to an outside lab. This speeds things up, but it also means clinics need ways to check that their machines are working correctly.
One standard way to check a machine is to run a “quality assessment sample” — a prepared blood sample with known values. If the machine reads it correctly, you know it’s working. If the machine gives unexpected results, something may be off.
The problem is that these quality samples have to be prepared and stored before use. And if storage degrades the sample, the check itself becomes unreliable. Researchers wanted to know: which storage conditions best preserve canine blood for this purpose?
How the Study Was Designed
Researchers collected blood samples from 5 healthy dogs. The samples were treated with a combination of anticoagulants — chemicals that keep blood from clotting in the tube so it can be analyzed later. The anticoagulants used were CPDA (citrate-phosphate-dextrose-adenine, a common preservative) and EDTA (ethylenediaminetetraacetic acid, a standard blood-tube additive).
The team then stored samples under different temperature conditions and tested them over time to see which cell measurements stayed consistent and which ones drifted.
Because this was a controlled laboratory study focused on sample handling — not on treating sick dogs — the findings speak to lab quality practices rather than to patient care directly.
What the Researchers Found
White Blood Cells and Platelets Did Better at Room Temperature
The study found that white blood cell counts and platelet counts were more stable when stored at room temperature compared to refrigeration. For quality assessment purposes, this suggests that room temperature storage may be better for preserving these particular measurements.
This matters because both WBCs and platelets are sensitive indicators on a CBC. If a stored sample’s WBC or platelet numbers drift during storage, a clinic might think their analyzer is off when it actually isn’t — or worse, not catch a real malfunction.
Red Blood Cell Values Held Up Better in the Refrigerator
On the other side, red-cell measurements — the values related to how many red cells are in the blood and how they look — were more stable when the samples were kept refrigerated.
This suggests a trade-off: no single storage temperature is best for all CBC components. Different parts of the blood behave differently depending on how they’re kept.
A Higher EDTA Concentration Helped Reduce Drift Over Time
The study also found that using a higher concentration of EDTA in the sample was linked to less variability in results over time. EDTA works by binding to calcium ions in the blood, which stops the clotting process. A stronger EDTA concentration appeared to help keep the sample more consistent as time passed.
What Storage Findings Mean for Your Dog’s Lab Work
This Is About Lab Quality, Not Home Care
To be clear: this study is about how vet clinics and diagnostic labs handle blood samples — not about anything a pet owner can or should do at home. You don’t draw your dog’s blood or store it yourself. But understanding this research gives you useful context.
If your dog’s CBC results ever come back with unexpected values and your vet wants to repeat the test, storage conditions are one of several reasons why results can vary between samples. It’s not always about what’s happening inside your dog — sometimes the path the sample took matters too.
Better Lab Protocols Could Mean More Trustworthy Results
The broader impact of this kind of research is standardization. If labs and clinics follow optimized storage protocols based on studies like this one, the quality-check samples used to calibrate CBC machines will be more reliable. And more reliable calibration means more trustworthy results for your dog.
Questions Worth Asking Your Veterinarian
If you’re curious about how your vet clinic handles blood work quality:
- Ask whether they use point-of-care analyzers or send samples to an outside lab
- Ask how quickly samples are analyzed after collection — timing can affect results
- If a result surprises you, it’s always reasonable to ask whether a repeat test would be helpful
Study Limitations to Keep in Mind
This study was deliberately small — just 5 dogs — and was entirely laboratory focused. The researchers themselves noted that the findings don’t directly assess patient health outcomes. A study this size is useful for generating early insights and guiding future research, but the conclusions would need to be confirmed in larger studies with more dogs before becoming standard veterinary guidance.
The study also focused specifically on samples prepared for quality-assessment purposes, not on routine blood draws. Whether the same storage principles apply to every clinical scenario would require additional investigation.
Storage Temperature Shapes Which CBC Numbers Stay Reliable
A new study found that blood sample storage temperature is linked to how stable different CBC measurements are in dogs. White blood cell and platelet counts held up better at room temperature, while red-cell values were more stable when refrigerated. Higher EDTA concentration was also associated with less variability over time.
This research doesn’t change what you need to do as a dog owner today — but it highlights that the reliability of your dog’s blood test results depends on more than just the machine. How a sample is stored and handled before analysis is part of the picture. Research like this helps veterinary practices sharpen their quality protocols so the numbers you see on your dog’s lab report are as accurate as possible.
This article summarizes peer-reviewed research for educational purposes. Always consult with your veterinarian for personalized advice about your pet’s health and behavior.
