Biological variation in random and leukotriene B4-directed migration of canine neutrophils

Seasonal, sexual, parental and age-related effects on peripheral blood neutrophil migration were studied in 25 dogs. Random and chemotactic movements were estimated by measuring migration towards buffer and leukotriene B4, respectively. Significant effects were seen only in the comparison between the two sexes. Neutrophils from bitches exhibited 19% greater random migration but 10% smaller chemotactic responsiveness than neutrophils from male dogs. A progesterone-mediated suppression of chemotaxis is hypothesized in metoestral bitches. It is concluded that the observed differences are probably too subtle to play any role in combatting bacterial infections, but may constitute a source of bias in the evaluation of isolated cases of disease-associated defective chemotaxis.