Microfilariae levels decline in response to CBR417 and CBR490 treatment. Mf count per 10 μL of blood drawn from jirds infected with L. sigmodontis and that have been treated with doxycycline (DOX), CBR417, CBR490, vehicle control or left untreated. A: 13-week-infected jirds were either left untreated () or treated bi-daily (BID) with 40 mg/kg doxycycline for 14 days (), once per day (QD) with 50 mg/kg CBR417 for 4 days () or BID with 75 () or 25 mg/kg () CBR490 for 7 days. B: 16-week-infected jirds were either treated BID with vehicle control for 7 days (), BID with 40 mg/kg doxycycline for 14 days (), QD with 50 (), 20 () or 10 () mg/kg CBR417 for 7 days, QD with 20 () or 10 () mg/kg CBR490 for 7 days or BID with 25 mg/kg CBR490 for 7 days (). Jirds were sacrificed 16 (A) or 18 (B) weeks after treatment. N = 5–6 per group.