Quantitative buffy coat analysis for hematologic measurements of canine, feline, and equine blood samples and for detection of microfilaremia in dogs.

This research study evaluated the efficiency of the Quantitative Buffy Coat (QBC) method for analyzing blood samples from dogs, cats, and horses. The method was found to work rapidly and provide useful results, but had some limitations with certain measurements, especially in canine samples.

Analysis Method

• The research employed the Quantitative Buffy Coat (QBC) method, a technique that separates blood cells by density through centrifugation, to analyze blood samples from 175 dogs, 125 cats, and 125 horses.
• The results of this technique are expressed as band lengths for various components of the blood – red blood cells (RBC), granulocytes, nongranulocytes, and platelets.
• This method’s main advantage is the speed with which it can provide results, making it suitable for rapid hematological screening.

Correlation of Results and Shortcomings

• The band lengths obtained from the QBC method were compared to those derived from reference laboratory methods. The correlation coefficients ranged from 0.72 to 0.99. This suggests that for most measurements, the QBC method aligned well with the standard laboratory procedures.
• The QBC results for packed cell volume (PCV), granulocyte count, and total white blood cell (WBC) count were highly accurate, with a correlation coefficient equal to or greater than 0.93.
• However, the QBC method showed lower correlation for platelet and nongranulocyte counts, indicating potential inaccuracies in these measurements.
• One key issue encountered during the study was the poor separation of the red blood cell-granulocyte interface in 17% of the dog blood samples. This issue interfered with the measurement of band lengths, effectively limiting the method’s effectiveness.

Detection of Microfilaremia

• In addition to general hematological measurements, the QBC system was also evaluated for the detection of microfilaremia, specifically the presence of Dirofilaria immitis microfilariae (larval heartworms) in dogs.
• The QBC method demonstrated 100% sensitivity to microfilariae counts as low as 160 microfilariae/ml of blood, attesting to the method’s effectiveness in detecting this parasite in canine blood samples.