Comparative speed of kill of sarolaner (Simparica®) and afoxolaner (NexGard®) against induced infestations of Ixodes holocyclus on dogs

Table 1 Mean live Ixodes holocyclus counts and efficacy relative to placebo at 8, 12, 24 and 48 h after treatment for dogs treated with a single oral dose of sarolaner or afoxolaner on Day 0

Treatment		Tick counting time points post-treatment
Treatment		8 h	12 h	24 h	48 h
Placebo	Range	21–28	20–28	19–28	19–30
	Arithmetic mean (AM)	24.13	24.25	23.63	23.75
	Geometric mean GM)^a	24.00	24.13	23.47	23.53
Sarolaner	Range	0–13	0–8	0–0	0–0
	Arithmetic mean (AM)	5.13	1.63	0	0
	AM Efficacy (%)	78.87	93.30	100	100
	Geometric mean (GM)^a	3.32	0.76	0	0
	GM Efficacy (%)	86.17	96.87	100	100
	Test statistic vs placebo	t ₍₉₎ = 5.02	t ₍₈₎ = 8.65	t ₍₃₄₎ = 17.31	t ₍₁₇₎ = 58.45
	P-value vs placebo	0.0007	< 0.0001	< 0.0001	< 0.0001
Afoxolaner	Range	10–28	1–13	0–2	0–0
	Arithmetic mean (AM)	20.13	5.00	0.38	0
	AM Efficacy (%)	17.01	79.38	98.41	100
	Geometric mean (GM)^a	18.89	3.63	0.25	0
	GM Efficacy (%)	21.28	84.95	98.93	100
	Test statistic vs placebo	t ₍₉₎ = 0.65	t ₍₈₎ = 6.24	t ₍₄₆₎ = 11.78	t ₍₁₇₎ = 58.45
	P-value vs placebo	0.5302	0.0003	< 0.0001	< 0.0001
	Test statistic vs sarolaner	t ₍₉₎ = 4.36	t ₍₁₅₎ = 2.40	t ₍₇₀₎ = 0.74	t ₍₁₇₎ = 0.00
	P-value vs sarolaner	0.0018	0.0303	0.4622	1.0000

ISSN: 1756-3305