Calculated hematocrit is determined by multiplying the red cell count by the mean cell volume. The hematocrit is slightly more accurate, as the PCV includes small amounts of blood plasma trapped between the red cells.
A low red blood cell count, low hematocrit, or low hemoglobin all point to anemia, which can leave your mouse weak and tired. This can stem from various causes.Blood sample collection in small laboratory animals PMC. Interpreting blood profiles in non-domestic small mammals.

Differential blood count: Small mammals generally have a lymphocytic blood count (exception: ferrets, which have a 50:50 ratio).Blood gas measurement in small mammals is generally only performed in clinics with appropriate equipment.

Red blood cell count.A low RBC count could also indicate a vitamin B6, B12 or folate deficiency. It may also signify internal bleeding, kidney disease or malnutrition (where a person's diet does not contain enough nutrients to meet their body's needs).
+ Compl. Blood Count BS+HB,EB/0,5ml 25.30 3011 Fructosamine.(Small Mammal Screening (large) + E. cuniculi Profile).