Dose-titration challenge of young pregnant sheep with Neospora caninum tachyzoites

Detection of Neospora caninum DNA in semen of experimental infected rams with no evidence of horizontal transmission in ewes

“…IDEXX Chekit is an indirect ELISA which detects antibodies against N. caninum in ruminants and has been used in studies in sheep and goats (Reichel et al, 2008;Weston et al, 2009;Bishop et al, 2010;Czopowicz et al, 2011). According to the manufacturer's instructions an S/P value of 30-40% is considered as suspect positive and over 40% is considered as positive for N. caninum.…”

“…Repeat abortions in subsequent years have also been reported (Jolley et al, 1999). In addition, studies have shown that experimentally infected sheep will seroconvert and abort in a dose dependent manner (Buxton et al, 1998(Buxton et al, , 2001Weston et al, 2009). These reports suggest that N. caninum infections can and do occur and cause disease, although it has generally not been regarded as a significant cause of abortion in sheep Otter et al, 1997;Buxton et al, 1998;Helmick et al, 2002).…”

Vertical transmission in experimentally infected sheep despite previous inoculation with Neospora caninum NcNZ1 isolate

“…Single tube nested N. caninum PCR reactions were performed as described by Ellis et al (1999) to amplify the ITS1 region using the internal (NR1 and NS2) and external (NF1 and SR1) primer pairs as described by Weston et al (2009). PCR products were run on a 1.5% (w/v) ultra-pure agarose gel (Invitrogen, CA, USA) containing ethidium bromide at 100 V for 45 min and visualized under UV light on a transilluminator.…”

“…(Howe et al, 2012(Howe et al, , 2008Hassig et al, 2003;Kobayashi et al, 2001). Experimental studies have shown that sheep will seroconvert, abort in a dose dependent manner and may have repeated abortions in subsequent pregnancies (Weston et al, 2009;Buxton et al, 2001;Jolley et al, 1999). Nevertheless, the role of N. caninum as a significant pathogen and abortifacient in sheep is still unclear and knowledge about its epidemiology, especially the mode of transmission of neosporosis in sheep, is limited (Helmick et al, 2002;Otter et al, 1997).…”

“…One experimental study found that using the local NcNZ isolates, sheep aborted in a dose dependent manner and at least 5000 tachyzoites were required to induce abortion when inoculated into ewes at Day 90 of gestation (Weston et al, 2009). An additional study has shown that transmission via semen is unlikely to occur, even when rams were inoculated with a large challenge (Syed-Hussain et al, 2013).…”