Effectiveness of eprinomectin 0.5% pour-on against gastrointestinal nematodes in naturally infected cattle (original) (raw)
Related papers
Veterinary Parasitology, 2004
Forty spring-calving cows and heifers (20 of each) were allowed to acquire infection with gastrointestinal (GI) nematodes naturally during grazing. The control group (10 cows and 10 heifers) were compared with 20 similar animals treated with eprinomectin in order to evaluate the effect of GI nematodes on grazing behaviour, milk production, body condition score and live weight. The animals were paired according to parity and milk yield during the week prior to treatment, then within replicate pair randomly allocated to a different treatment group. The grazing area was subdivided into 20 replicated paddocks of equivalent size and topography. Grazing pairs of either control or treated animals were randomly assigned to each paddock over the duration of the study (one pair per paddock). Grazing behaviour was recorded for both groups over a 10-day period commencing 4 days after treatment with eprinomectin. Milk yield was recorded daily and milk quality was recorded weekly. Live weight and body condition score were recorded on the day of allocation, the day of initial treatment and thereafter at weekly intervals until the end of the 4-week trial. Faecal samples were collected from each animal prior to, and after, allocation and submitted for counts of nematode eggs. Additional faecal samples were taken at the end of the study for culture and nematode identification. Individual faecal samples were also analysed for residual digestibility. Pasture samples for nematode larval counts were taken at the same time as faecal sampling. The parasitological results showed low levels of faecal nematode egg output throughout the study, with
Veterinary Parasitology: X, 2019
The effect of pour-on eprinomectin administration on milk yield and somatic cell counts was studied in dairy ewes located on twelve farms in mainland Greece. On each farm, the selected ewes were randomly divided into three similar groups. Group 1 consisted of 10-15 untreated ewes (control group), Group 2 consisted of 10-13 ewes treated with a single dose of eprinomectin at Day 0 and Group 3 consisted of 6 ewes repeatedly treated with eprinomectin at Days 0, 42 and 70. Faecal egg counts and coprocultures were performed on Days 0, 7, 14, 28, 42, 56, 70, 84 and 98. The milk yield and somatic cell counts were measured. The topically administered eprinomectin was highly effective against gastrointestinal nematodes up to 42 days post treatment (94.1% and 99.7% for Groups 2 and 3, respectively). This beneficial effect was extended from Day 42 to 98, in ewes of Group 3. Ewes treated once or thrice presented an increase of daily milk yield by ca. 5% (50 mL/day) and 11% (105 mL/ day), respectively, compared to untreated ewes. At the same frame, a significant decrease in somatic cell counts was observed in the eprinomectin treated ewes compared to the untreated ones. In conclusion, this study confirmed the high antiparasitic efficacy and the beneficial effect of pour-on eprinomectin on the milk yield and somatic cell counts in dairy ewes under semi-intensive management.
Veterinary Parasitology, 2020
The objective was to investigate the effect of injectable eprinomectin on milk yield and quality of dairy ewes naturally infected with gastrointestinal nematodes when grazing in communal pastures. Onehundred and fifty (150) clinically healthy adult lactating ewes, equally selected from 3 farms, were included in the study. On day-7, the ewes on each farm were randomly allocated into 2 equal groups of 25 animals (n=50): Control group (C) and Treated group (T). On day 0, ewes in group T were given a single subcutaneous injection of eprinomectin at a dose rate of 0.2 mg/kg bodyweight. Ewes in group C were left untreated during the whole experiment. Ewes in group T with a fecal egg count (FEC) >300 eggs per g on day +60 were treated again. Fecal samples were individually collected on days-7, 0, +30, +60, +90, +120 for FEC estimations and coprocultures. On days-7, 0, +30, +60 and +90, individual milk yield (MY) was recorded using ICAR approved volumetric milk meters. Energy corrected milk yield (ECMY) for 6% fat was also calculated. Moreover, individual milk samples were collected on each day for determination of chemical composition [fat (F%), protein (P%) and lactose (L%) content] and somatic cell counts (SCC). On each day, individual fat and protein yield (FY and PY, respectively) were calculated. Total lactation MY, total ECMY, total FY and total PY were computed. The most prevalent parasite at pre-treatment and post-treatment days was Haemonchus spp. The overall efficacy on days +30 and +90 was 97.27 % and 98.80 %, respectively. In two out of the three farms, 80 % and 91.3 % of T ewes received a second treatment on day +60, due to high parasitic burden. Treatment had a significant effect (P=0.033) on MY with an average benefit of 8%. No significant effects of treatment were observed on the other parameters, although values were constantly numerically higher for treated ewes compared to control ones. In this field trial, injectable eprinomectin had a high overall efficacy and a beneficial effect on daily milk yield.
Persistent efficacy of topical eprinomectin against nematode parasites in cattle
Parasitology …, 2000
Six studies were conducted to evaluate the persistent ecacy of eprinomectin pour-on against experimental challenges with infective nematode larvae in calves. In each study, calves were randomly assigned to one untreated group and up to four test groups, which were treated with eprinomectin at 500 lg/kg body weight at weekly intervals before single bolus challenge. The calves were necropsied approximately 4 weeks after challenge infection for nematode recovery. Eprinomectin pour-on provided ³90% ecacy against challenge with Haemonchus placei, Trichostrongylus axei and T. colubriformis at 21 days after treatment and against Cooperia oncophora, C. punctata, C. surnabada, Dictyocaulus viviparus, Nematodirus helvetianus, Oesophagostomum radiatum and Ostertagia ostertagi at 28 days after treatment.
Veterinary parasitology, 2013
The efficacy of eprinomectin in an extended-release injection (ERI) formulation was evaluated against infections with third-stage larvae or eggs of gastrointestinal and pulmonary nematodes in cattle under 120-day natural challenge conditions in a series of five studies conducted in the USA (three studies) and in Europe (two studies). For each study, 30 nematode-free (four studies) or 30 cattle harboring naturally acquired nematode infections (one study) were included. The cattle were of various breeds or crosses, weighed 107.5-273 kg prior to treatment and aged approximately 4-11 months. For each study, animals were blocked based on pre-treatment bodyweight and then randomly allocated to treatment: ERI vehicle (control) at 1 mL/50 kg bodyweight or Eprinomectin 5% (w/v) ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg) for a total of 15 and 15 animals in each group. Treatments were administered once on Day 0 by subcutaneous injection in front of the shoulder. In each study, all a...
Veterinary parasitology, 2013
A series of 10 dose confirmation studies was conducted to evaluate the persistent activity of an extended-release injectable (ERI) formulation of eprinomectin against single point challenge infections of gastrointestinal and pulmonary nematodes of cattle. The formulation, selected based on the optimal combination of high nematode efficacy, appropriate plasma profile, and satisfactory tissue residue levels, includes 5% poly(D,L-lactide-co-glycolic)acid (PLGA) and is designed to deliver eprinomectin at a dose of 1.0mg/kg bodyweight. Individual studies, included 16-30 cattle blocked based on pre-treatment bodyweight and randomly allocated to treatment with either ERI vehicle or saline (control), or the selected Eprinomectin ERI formulation. Treatments were administered once at a dose volume of 1 mL/50 kg bodyweight by subcutaneous injection in front of the shoulder. In each study, cattle were challenged with a combination of infective stages of gastrointestinal and/or pulmonary nematod...
Parasitology Research, 2012
A study was conducted to confirm the efficacy of topical eprinomectin against nematodes and to evaluate the pharmacokinetics in cattle prevented from having physical contact with other cattle and from self-grooming. Sixteen male Brown Swiss calves were infected with larvae of recently isolated nematode parasites. Inoculation was scheduled so that the nematodes were expected to be adults at the time of treatment. Animals were blocked based on pretreatment body weight and randomly allocated to the untreated control group or the group treated with EPRINEX® Pour-On (Merial; 0.5 mg eprinomectin per kilogram body weight). Plasma samples were collected prior to and between 1 and 21 days following treatment and analysed for eprinomectin (B1a component) concentrations. For parasite recovery, identification and counting, animals were humanely euthanized 21 days after treatment. Calves treated with eprinomectin had significantly (p<0.05) fewer (>99 % reduction) adult Dictyocaulus viviparus, Bunostomum phlebotomum, Cooperia oncophora, Cooperia surnabada, Cooperia punctata, Nematodirus helvetianus, Oesophagostomum radiatum, Ostertagia ostertagi, Ostertagia lyrata, and Trichostrongylus axei and inhibited fourth-stage Nematodirus and Ostertagia larvae than the controls. The main pharmacokinetic parameters of eprinomectin B1a were: AUC(inf), 124±24 day ng/mL; T 1/2 , 5.2±0.9 days; and C max , 9.7±2.2 ng/mL. Individual maximal concentrations were observed 3-7 days after treatment. This study confirmed the continued high level of efficacy of topically administered eprinomectin against a wide range of recently isolated nematodes. In addition, this study demonstrates that oral ingestion is not required to achieve adequate exposure for efficacy following topical administration of eprinomectin.
BMC veterinary research, 2017
The anthelmintic efficacy of the 0.5% w/v topical formulation of eprinomectin (EPN), EPRINEX® Pour-on (Merial) when administered at 1 mg/kg body weight was evaluated in sheep in two dose confirmation laboratory studies and one multicenter field study. In addition, the pharmacokinetics of EPN when administered at that dosage to adult sheep was determined. In the two dose confirmation studies, which included 10 sheep each, sheep treated with topical EPN had significantly (p < 0.05) fewer of the following nematodes than the untreated sheep with overall reduction of nematode counts by >99%: adult Dictyocaulus filaria, Haemonchus contortus, Teladorsagia circumcincta(pinnata/trifurcata), Trichostrongylus axei, T. colubriformis, T. vitrinus, Cooperia curticei, Nematodirus battus, Strongyloides papillosus, Chabertia ovina and Oesophagostomum venulosum, and inhibited fourth-stage Teladorsagia larvae. A total of 196 sheep harboring naturally acquired gastrointestinal nematode infections...
Small Ruminant Research, 2015
Two controlled studies were performed to assess the efficacy and pharmacokinetics of topical 0.5% w/v eprinomectin (EPRINEX ® Pour-on, Merial) against nematode infections of goats. Each study included 16 male castrated goats, less than one year old, harboring induced infections of adult gastrointestinal and pulmonary nematodes. Following blocking on pre-treatment bodyweight and random allocation to one of two groups, half the goats in each study were treated once with eprinomectin (1 mg/kg bodyweight, administered topically), and half remained untreated and served as controls. Plasma concentrations of eprinomectin were determined in blood samples collected prior to and at multiple time points up to necropsy. Efficacy was determined based on the nematode counts of the animals following necropsy 14 days after treatment.
Veterinary Record, 1999
A field study was undertaken on three Swiss sheep farms (A, B, C) to evaluate the efficacy of a long-acting moxidectin formulation (Cydectin® 2% LA) against gastrointestinal nematodes (GIN). Naturally infected ewes (all three farms) and their winter-borne lambs (farms A and B) were allocated to two groups (MOX, CON). At day 0 ewes of the MOX-groups were treated with 1 mg moxidectin s.c. CON-and MOX-groups were grazed on separate pastures and were sampled for faeces and blood at 28-day intervals. Larval cultures demonstrated that Haemonchus contortus was the dominant GIN-species in ewes throughout the season. Over the entire observation period faecal egg count (FEC) of the MOX-ewes in farms A, B, C was 56%, 84% and 87% less than the CON-ewes (p < 0.05). FEC of lambs grazing with MOX-ewes was reduced in farms A and B by 56% and 61%, respectively (p < 0.05), compared with the respective CON-groups. None of these lambs received anthelmintic treatment during the experiment. Therefore, the differences were due to an indirect effect mediated by the lower pasture contamination with GIN-larvae. These were reduced by 73%, 81% and 74% in farms A-C respectively compared to the CON-groups (p < 0.05). In farm B, where lambs remained with their mothers during the entire grazing season, these differences were also reflected by a higher daily weight gain (p < 0.05) and reduced pepsinogen levels in lambs of treated ewes. This strategy offers an interesting potential for expanding refugia by propagation of GIN in untreated lambs.