Does Evaluation of in Vitro Microfilarial Motility Reflect the Resistance Status of Dirofilaria Immitis Isolates to Macrocyclic Lactones?

Several reports have confirmed that macrocyclic lactone-resistant isolates of Dirofilaria immitis are circulating in the United States; however, the prevalence and potential impact of drug resistance is unknown. We wished to assess computer-aided measurements of motility as a method for rapidly assessing the resistance status of parasite isolates.