The effectiveness of VALCOR® against gastrointestinal nematodes and ectoparasites was demonstrated in five dose confirmation studies and a multi-site field study and is described below. VALCOR®-treated cattle (N = 373) had either naturally or artificially acquired infections or infestations originating from a wide range of geographical settings. These studies demonstrate that VALCOR® is effective against a variety of internal and external parasites. Across three dose confirmation studies and a multi-site field study, the VALCOR®-treated animals had a fecal egg count reduction between 99.9% and 100% when the pre-treatment and post-treatment arithmetic means of fecal egg counts were compared.
a. Multi-site Study
A multi-site study was conducted to evaluate the effectiveness of VALCOR® against naturally acquired gastrointestinal nematodes in a field setting. In this six-site study, 425 cattle (steers, heifers, pregnant heifers, pregnant cows and late lactation cows) were enrolled and randomized to one of two treatment groups: saline, N = 106, (0.04 mL/kg); VALCOR®, N = 319, (0.2 mg/kg doramectin; 6 mg/kg, levamisole hydrochloride (HCl). Effectiveness of VALCOR® was achieved with >99% reduction in fecal egg counts compared to the saline-treated group on Day 14. Percent efficacy, by site, ranged from 99.4% to 100.0% on Day 14.
b. Dose Confirmation Studies
Artificial Nematodirus helvetianus Challenge Study
A study was conducted to evaluate the effectiveness of VALCOR® against cattle infected with an artificial N. helvetianus challenge. In this study, 24 artificially infected cattle (9-week old Holstein steers) were enrolled and randomized to one of three treatment groups: saline group, N = 8, (0.04 mL/kg); DECTOMAX®, N = 8, (0.2 mg/kg doramectin); VALCOR®, N = 8, (0.2 mg/kg doramectin; 6 mg/kg, levamisole HCl). Effectiveness of VALCOR® was achieved with 100% efficacy against adult N. helvetianus compared to the saline-treated group with 0% efficacy and the DECTOMAX®-treated group with 4.9% efficacy on Day 14.
Nematodirus helvetianus and Cooperia oncophora Natural Infection Studies
A study was conducted to evaluate the effectiveness of VALCOR® against cattle naturally infected with N. helvetianus and C. oncophora. In this study, 36 naturally infected cattle (4-10 month old, male and female beef and dairy crossbred) were enrolled and randomized to one of three treatment groups: saline, N = 12, (0.04 mL/kg); DECTOMAX®, N = 12, (0.2 mg/kg doramectin); VALCOR™, N = 12, (0.2 mg/kg doramectin; 6 mg/kg, levamisole HCl). Effectiveness of VALCOR® was achieved with 100% efficacy against adult N. helvetianus and 100% efficacy against C. oncophora compared to the saline-treated group with 0% efficacy and the DECTOMAX® group with 87.9% and 99.4% efficacy against N. helvetianus and C. oncophora, respectively, on Day 14.
A second study was conducted to evaluate the effectiveness of VALCOR® against cattle naturally infected with N. helvetianus and C. oncophora. In this study, 30 naturally infected cattle (7-month old, male and female beef crossbred) were enrolled and randomized to one of three treatment groups: saline, N = 10, (0.04 mL/kg); DECTOMAX®, N = 10, (0.2 mg/kg doramectin); VALCOR®, N = 10, (0.2 mg/kg doramectin; 6 mg/kg, levamisole HCl). Effectiveness of VALCOR™ was achieved with 99.1% efficacy against adult N. helvetianus and 99.7% efficacy against C. oncophora compared to the saline-treated group with 0% efficacy and DECTOMAX® group with 25.4% and 49.3% efficacy, against N. helvetianus and C. oncophora, respectively, on Day 14.
Sucking Lice Natural Infestation Studies
A study was conducted to evaluate the effectiveness of VALCOR® against cattle naturally infested with sucking lice (Linognathus vituli, Haematopinus eurysternus, and Solenopotes capillatus). In this study, 24 naturally infested cattle (beef and dairy breed females and castrate males) were enrolled and randomized to one of two groups: sterile water group, N = 12 (0.04 mL/kg) and VALCOR™, N = 12, (0.2 mg/kg doramectin; 6 mg/kg, levamisole HCl). Effectiveness of VALCOR® was achieved with 99.9% efficacy against immature and adult sucking lice up to 56 days after treatment.
A second study was conducted to evaluate the effectiveness of VALCOR® against cattle naturally infested with sucking lice (L. vituli). In this study, 24 naturally infested cattle (beef and dairy breed females and castrate males) were enrolled and randomized to one of two groups: saline group, N = 12 (0.04 mL/kg) and VALCOR®, N = 12, (0.2 mg/kg doramectin; 6 mg/kg, levamisole HCl). Effectiveness of VALCOR® was achieved with 99.4% efficacy against immature and adult sucking lice up to 56 days after treatment