Objective: To determine whether dogs given garlic extract developed hemolytic anemia and to establish the hematologic characteristics induced experimentally by intragastric administration of garlic extract.
Animals: 8 healthy adult mixed-breed dogs.
Procedure: 4 dogs were given 1.25 ml of garlic extract/kg of body weight (5 g of whole garlic/kg) intragastrically once a day for 7 days. The remaining 4 control dogs received water instead of garlic extract. Complete blood counts were performed, and methemoglobin and erythrocyte-reduced glutathione concentrations, percentage of erythrocytes with Heinz bodies, and percentage of eccentrocytes were determined before and for 30 days after administration of the first dose of garlic extract. Ultrastructural analysis of eccentrocytes was performed.
Results: Compared with initial values, erythrocyte count, Hct, and hemoglobin concentration decreased to a minimum value on days 9 to 11 in dogs given garlic extract. Heinz body formation, an increase in erythrocyte-reduced glutathione concentration, and eccentrocytes were also detected in these dogs. However, no dog developed hemolytic anemia.
Conclusions and clinical relevance: The constituents of garlic have the potential to oxidize erythrocyte membranes and hemoglobin, inducing hemolysis associated with the appearance of eccentrocytes in dogs. Thus, foods containing garlic should not be fed to dogs. Eccentrocytosis appears to be a major diagnostic feature of garlic-induced hemolysis in dogs.