Inability of Dirofilaria immitis infective larvae from mosquitoes fed on blood from microfilaremic dogs during low-dose and short-treatment regimens of doxycycline and ivermectin to complete normal development in heartworm naïve dogs

Table 1 Dirofilaria immitis recovery for dogs infected with L₃ from mosquitoes fed on blood from dogs treated with doxycycline plus ivermectin and untreated controls

Study	Dog	Group	Study day mosquitoes infected	No. L3 per dog	Necropsy days Pl	Male	Female	Total
No. adult heartworms
M-A	UIAQ	1-M^a	22	50	183	0	0	0
	9285	1-M	22	50	183	0	0	0
	9284	2-M	22	50	183	0	0	0
	147	2-M^b	22	50	183	0	0	0
	175	3-M^c	22	50	183	18	25	43
M-B	208	1-M	29	50	176	0	0	0
	209	1-M	29	50	176	0	0	0
	210	2-M	29	50	176	0	0	0
	211	2-M	29	50	176	0	0	0
M-C	140	1-M	42	30	163	0	0	0
	164	1-M	42	30	163	0	0	0
	SIBO	2-M	42	40	163	0	0	0
	144	2-M	42	40	163	0	0	0
	151	3-M	42	40	163	12	14	26

^aShort-term treatment: single, daily oral doses of doxycycline administered at 10 mg/kg for 30 days starting on Day 0 and monthly prophylactic doses of ivermectin (min., 6 mcg/kg) administered on Day 0 and Day 30
^bLong-term treatment: single, daily oral doses of doxycycline administered at 10 mg/kg (72–98 days) and bi-weekly doses of prophylactic doses of ivermectin (min. dose, 6 mcg/kg) administered orally every 2 weeks (6–7 doses) until individual dogs became amicrofilaremic
^cUntreated controls

ISSN: 1756-3305