Leukocyte changes associated with acute inflammation in chickens

Leukocyte changes in chickens with turpentine-induced inflammation were investigated sequentially at 0, 6, 12, and 24 hours and at 2, 3, 4, 7, and 14 days. During acute inflammation, significant leukocytosis and heterophilia developed by 6 hours and persisted through 7 days. The peak mean heterophil and leukocyte counts occurred at 12 hours and 3 days, respectively. Left shifts were present at 12 and 24 hours as detected by 100-cell leukocyte differential counts. Heterophil mean nuclear scores documented nuclear hyposegmentation (left shift) during early inflammation and nuclear hypersegmentation (right shift) during convalescence. Mean monocyte and lymphocyte counts peaked at 2 and 3 days, respectively. Basophil and eosinophil counts were erratic. Toxic changes of heterophils were most apparent during intense left shifts and consisted of cell swelling, degranulation, cytoplasmic vacuolation, and cytoplasmic basophilia. Cytoplasmic basophilia was the last aspect of toxic change to resolve. Ultrastructurally, toxic heterophils had intracellular edema, dissolution of granules, retention of ribosomes, nuclear membrane blebs, and decreased heterochromatin density. All inflammation-associated alterations in cell counts and morphology returned to baseline values and appearance by 14 days after turpentine administration.