**4. Leukocytes**

The total leukocytes count (TLC) and differential leukocytes count are important parameters to judge the body response against diseases. The TLC was 6.2 to 11.05, 8.5 ±1.42 thousand/µl in free range tigers while differential leukocyte counts (DLC) reflect the information of infectious manifestations. A leukocytosis may be physiologic mediated by endogenous release of epinephrine or corticosteroids or it may be pathologic response to a diseases process (reactive leukocytosis) or a result of a neoplastic change in the haematopoiesis (proliferative leukocytosis) while leucopenia is always pathologic event. Quantitative and qualitative changes in a particular type of leukocyte indirectly reflect the nature of disease process and the body response to it.

Jain (1986) reported physiologic factors such as fright and "emotional" disturbances as an immediate effect on TLC and DLC and may confined to interpretation of conditions. The normal response to the stress is decrease in lymphocytes and eosinophil numbers. In "emotional" leucocytosis, lymphocyte numbers are increased and equal or exceed neutrophil numbers while eosinophil commonly not affected. Meyers-Wallen et. al. (1984) observed the young cats normally have high lymphocyte counts and hence a greater tendency to develop lymphocytosis than the adults. This observation may also be attributed in the case of tigers as they belong to the member of same family with wild habitat as an escape behavior. Increases in neutrophil numbers due to physiologic influences are more pronounced in felines than in canines because of the difference in the intravascular distribution of neutrophils. Prasse et. al.(1973) have observed 3 times mean marginal pool of neutrophils of clinically healthy cats than the circulating pool whereas in dog it was about equal or slightly greater.

#### **4.1. The neutrophils**

234 Blood Cell – An Overview of Studies in Hematology

**Plate 2.** Tiger Blood smear stained with Modified Wright Stain x1000.

The total leukocytes count (TLC) and differential leukocytes count are important parameters to judge the body response against diseases. The TLC was 6.2 to 11.05, 8.5 ±1.42 thousand/µl in free range tigers while differential leukocyte counts (DLC) reflect the information of infectious manifestations. A leukocytosis may be physiologic mediated by endogenous release of epinephrine or corticosteroids or it may be pathologic response to a diseases process (reactive leukocytosis) or a result of a neoplastic change in the haematopoiesis (proliferative leukocytosis) while leucopenia is always pathologic event. Quantitative and qualitative changes in a particular type of leukocyte indirectly reflect the nature of disease

Jain (1986) reported physiologic factors such as fright and "emotional" disturbances as an immediate effect on TLC and DLC and may confined to interpretation of conditions. The normal response to the stress is decrease in lymphocytes and eosinophil numbers. In "emotional" leucocytosis, lymphocyte numbers are increased and equal or exceed

**4. Leukocytes** 

process and the body response to it.

Neutrophils considered as first line of defense against microbial infections and are important participants in inflammatory reactions. Shrivastav, et.al. (2011) encountered 57 to 75, 60 ±5.08 % with multi-lobed nuclei of 3-5 lobes while sometimes mono-lobed nuclei with pale to slightly pink granules in the cytoplasm in free range tigers( Plate3). Chandranaik, et.al. (2006) has also reported the segmented or multi lobed nuclei while Jain (1986) studied the sex chromatin in few neutrophils as the drumstick lobe in the female cats.

The changes in blood neutrophil differential count (Haden, 1935) is associated with many consequences related to infectious diseases. Several functions have been suggested for the contents of granules, as neutrophils are phagocytic cells and regulating adhesiveness and aggression hydroxyl radical formation and generation of compliment derived chemotactic factors while azurophilic granules are involved in modulation of inflammatory process (Gallin, et. al.1982). Condensation of nuclear chromatin leads to formation of darker-staining plaques separated by delicate, light-staining areas with slight brown colour cytoplasm.

#### **4.2. The eosinophils**

Shrivastav et.al. (2011) observed eosinophils contained small, uniformly round bright eosinophilic granules almost occupying the entire and clear cytoplasm (Plate 3). These cells were encountered 2 to 6, 4 ±1.21 % in free range tigers (Table 1). The nuclei of the cells were generally less lobulated than those of the neutrophils. The eosinophils are slightly larger than neutrophils. Chandranaik, et.al. (2006) also observed the larger eosinophils larger than neutrophils and lobulated nuclei with orange cytoplasm in tigers. Jain (1986) reported the granules of the eosinophil are rod-like in domestic cats and Cheetah (*Acinonyx jubatus*) while round granules in the eosinophils of Lion and Leopard. The eosinophils are commonly seen in prolonged parasitic infections or allergic disorders.

#### **4.3. The basophiles**

The basophile is a numerically insignificant but functionally important leukocyte that resemble with mast cells and it believed to share similar function as it is associated with allergic reaction, inflammatory process and immunocompitancy to the body fluids. Galli et. al. (1982) reported basophiles of cats have a limited capacity to phagocytised. Chadranaik et.al. (2006) have reported smaller basophiles than eosinophils with pale lavender pink stained cytoplasmic granules in physically restrained tigers. Jain (1986) observed the mature basophiles contains numerous small, round, lightly stained (pinkish or orangish) granules in light gray cytoplasm in experimental cats. The basophiles were rarely observed up to the size with 0 to 0.4 0.1 ±1.21 5 % in free range tigers.
