For example, Bissonnette et al. [94] described a MDR1(+/-) juvenile mixed breed dog which showed neurological toxicity including ataxia, tremor and depression after daily ivermectin application at 670 μg/kg after seven weeks of therapy, indicating that at least one intact MDR1 allele may protect the dog from acute neurotoxicity after high dose applications of ivermectin. This evidence concerns the gene ABCB1 and depressive symptom measurement.