Which test is used to determine the percentage of red blood cells within a volume of blood?

The packed cell volume (PCV) test is used to measure the proportion of red blood cells in a given volume of blood. This measurement is crucial because it indicates not only the overall health of the animal but also its hydration status and potential underlying health conditions. A higher or lower than normal PCV can provide insights into various medical issues, such as anemia, dehydration, or other hematological disorders.

In contrast, a complete blood count provides a broader range of information about multiple components of the blood, including white blood cells and platelets, not solely focusing on red blood cells. The hemoglobin test measures the amount of hemoglobin, a protein in red blood cells, but does not provide a percentage of the red blood cells themselves. The blood glucose test focuses on the level of glucose in the blood and is unrelated to red blood cell percentage. Thus, the packed cell volume test is the specific and relevant test for determining the percentage of red blood cells within a volume of blood.