Polymorphonuclear leukocyte function in cattle with left displaced abomasum with or without concurrent infections.

Cattle submitted to the University of Minnesota for surgical correction of left displaced abomasum (LDA) were examined for the in vitro phagocytic and bactericidal activities of their polymorphonuclear leukocytes (PMN). The PMN from cattle with LDA with or without concurrent infection had depressed phagocytic function when compared with PMN from healthy animals (controls). Those with concurrent infection had phagocytic activities lower than those in the group of cattle with LDA without any concurrent infection, and the former group was also observed to have depressed intracellular killing. Cattle with LDA complicated by infection were the only group in which phagocytic function was altered during surgical correction of LDA (and recovery). Treatment of PMN from both groups of affected cattle with levamisole in vitro enhanced intracellular killing, but had no effect on phagocytosis.