Changes to plasminogen activators and matrix metalloproteinase-9 in dogs with toxocarosis

The relationship between proteolytic enzymes and hematological response to infection was studied in five 1-month-old dogs inoculated experimentally with 2000 eggs of Toxocara canis. Moderate leukocytosis and marked eosinophilia occurred 14 days post-infection with T. canis. Plasminogen activators (PAs) and matrix metalloproteinase-9 (MMP-9) activity in serum was significantly different in dogs infected with T. canis, compared with controls. Urokinase-type PA (uPA) activity was positively correlated with eosinophilia, and tissue-type PA (tPA) and MMP-9 activity was negatively correlated with eosinophilia. However, there was no correlation between inflammation and MMP-2. The use of uPA, tPA or MMP-9 proteolytic enzymes as laboratory reference markers for toxocarosis requires further study.