. 2022 Oct 26;20:76–88. doi: 10.1016/j.ijpddr.2022.10.005

Table 2.

Estimates of strongylid Egg Reappearance Periods (ERP) following ivermectin treatment in horses over the course of four decades. The table includes all publications that either calculated the percent Fecal Egg Count Reduction (FECR) during weeks post ivermectin treatment or presented Fecal Egg Count data allowing this calculation to me made. The definition of ERP was the week post treatment, where the mean FECR fell below 90%.

Study	Country	Estimate (weeks)
Lumsden et al. (1989)^a	UK	10
Borgsteede et al. (1993)^a	Netherlands	7–11
Repeta et al. (1993)^b	USA	8
Kivipelto and Asquith (1994)^a	USA	>9
Taylor and Kenny (1995)^a	UK	8
Arbittier (1996)^a	USA	8
Boersema et al. (1996)^b	Netherlands	9
DiPietro et al. (1997b)^a	USA	8
Demeulenaere et al. (1997)^a	Belgium	>8
Boersema et al. (1998)^a	Netherlands	10
Rolfe et al. (1998)^b	Australia	7
Piché et al. (2001)^a	Canada	9
Mercier et al. (2001)^b	Australia and Brazil	7
Tarigo-Martinie et al. (2001)^b	USA	6
Martin-Downum et al. (2001)^a	USA	8 < 12
Cirak et al. (2005)^a	Turkey	8
von Samson-Himmelstjerna et al. (2007)^b	Germany	5
Lind et al. (2007)^a	Sweden	10
Molento et al. (2008)^b	Brazil	4
Lyons et al. (2008a)^a	USA	4 and 5
McFarlane et al. (2010)^a	USA	8
Lyons et al. (2011a)^a	USA	5–7
Lyons et al. (2011b)^a	USA	4 and 5
Larsen et al. (2011)^b	Denmark	6
Kyvsgaard et al. (2011)^b	Nicaragua	10
Francisco et al. (2012)^b	Spain	6 and 9
Relf et al. (2014)^b	UK	6
Geurden et al. (2014)^b	Belgium	6, 8, and >12
Geurden et al. (2014)^b	Italy	8 and > 12
Geurden et al. (2014)^b	Netherlands	4, 5, 6, 8, and >12
Sanna et al. (2016)^b	Italy	12 and 21
Shea Porr et al. (2017)^a	USA	8
Rosanowski et al. (2017)	New Zealand	4, 5, and 6
Molena et al. (2018)^a	UK	5
Baranova et al. (2022)^a	Russia	6
Nielsen et al. (2022c)^b	USA	5
Molento et al. (2022)^b	Brazil	5

FECR calculated from data presented.

FECR calculated by study authors