Lamb eimeriosis: Applied treatment protocols in dairy sheep production systems (original) (raw)
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Parasitology Research, 2013
Sheep coccidiosis is a pathology caused by protozoan parasites of the genus Eimeria spp. with clinical and economic effect especially in young animals (Ambrosi 1995; Pellérdy 1974). A field study was conducted to evaluate the efficacy of a metaphylactic treatment with toltrazuril 5 % suspension (Baycox ® , Bayer) in comparison with diclazuril (Vecoxan ® , Janssen-Cilag) and untreated controls against naturally acquired Eimeria infections in housed lambs. A total of 170 animals, aged 24 to 34 days and randomly divided in three homogeneous groups, were included in the study. The assessment of treatment efficacy was based on total faecal oocyst excretion (opg) and count reduction (FOCR) in the two groups of animals treated with toltrazuril (TOLT) and diclazuril (DICL) compared with untreated control group (C). The animals treated with toltrazuril showed a considerably lower mean opg to that of group C (5.78 opg versus 144.62 opg) (p < 0.05) and a FOCR of 97.7 %. The higher efficacy (99.23 %) was observed at 15 days post treatment; however, the average efficacy of the S164 Protozoa drug remained extremely high (> 90 %) for all the study. The lambs treated with diclazuril showed an intense, persistent oocyst excretion with average levels of 97.54 opg, (p < 0.05). This study demonstrates the good efficacy of toltrazuril administered orally to lambs in the prepatent period in subclinical natural Eimeria infections in housed lambs.
Epidemiology of Eimeria infections in an Austrian milking sheep flock and control with diclazuril
Veterinary parasitology, 2005
In a flock of milking sheep from Styria (Austria), the dynamics of Eimeria oocyst excretion was monitored in the lambing season 2003-2004 and a treatment trial with 1 mg/kg diclazuril (single dose on day 0 of study) was conducted in two groups of early weaned lambs. Adult animals (n = 30 ewes, 30 yearlings) excreted oocysts of different species (weekly prevalences from week -7 ante partum to week 5 post-partum: ewes 20-60%, yearlings 38-73%) in low intensities (< or = 6000 oocyst per gram of faeces, highest values in weeks -1 and -4) without clinical signs. Ewes excreted significantly fewer oocysts than yearlings. Lambs in the first group (n = 32 treated animals, 32 controls) excreted oocysts from the seventh day of sampling (average age on day 0: 28 days), those in the consecutive group (n = 32 treated animals, 30 controls) already excreted oocysts on day 0 (average age: 34 days). Treatment resulted in significant reduction of the overall excretion rates on days 7-21 of study co...
Parasitology Research, 2017
This study evaluated the efficacy and the economic viability of two anticoccidial treatment regimens tested in lambs naturally exposed to Eimeria spp. re-infections in a grazing system during a 140-day period. Twenty-four suckling lambs were distributed into three groups based on the individual count of oocysts per gram of feces (OPG) and body weight. Animals were treated with toltrazuril 5% (20 mg/kg) at 14-(GI) or 21day (GII) intervals, and GIII was kept as untreated control. A cost-benefit analysis of each treatment regimen was calculated. Additionally, economic analysis was performed on four hypothetical scenarios, in which lambs could be having 10, 25, 50, or 85% decrease in their expected body weight gain due to clinical. Efficacy of toltrazuril against Eimeria spp. was 96.9-99.9% (GI) and 74.2-99.9% (GII). E. ovinoidalis was most frequently identified, but no clinical signs of coccidiosis were observed in lambs. There were no differences in weight gain among the groups. The cost of treatment per lamb was 13.09(GI)and13.09 (GI) and 13.09(GI)and7.83 (GII). The estimation model showed that the cost-benefit ratio favored treatment with toltrazuril when lambs fail to gain weight. In the studied flock, the break-even point for toltrazuril administered at 14-day intervals was reached with 85% decrease in mean weight gain. In conclusion, toltrazuril can be used at 14-day intervals to control Eimeria spp. (re)-infection in lambs raised on pasture. This treatment regimen was not economically feasible for subclinical coccidiosis; however, it may be feasible when used to prevent weight loss caused by clinical coccidiosis.
Small Ruminant Research
This trial determined the effect of a sustained-release intra-ruminal sodic sulfamethazine (SMZ) bolus on the Eimeria spp. oocyst output and the cumulative live-weight gain (CLWG) of naturally infected lambs in two different production systems (penned and penned-grazing). Forty male Pelibuey lambs (2-2.5 months old), naturally infected with Eimeria spp., were randomly included in four groups of 10 animals at weaning: (a) penned with SMZ bolus treatment (P-B), (b) penned untreated (P-U), (c) penned-grazing with bolus treatment (PG-B), and (d) penned-grazing untreated (PG-U). Treated lambs (P-B and PG-B) were dosed orally on day 0 with a single SMZ bolus (28.5% of SMZ). Lambs in the PG-U and PG-B groups were allowed to graze 10 h/day. Faecal samples and live-weights were obtained from each lamb on days 0, 8 and every 7 days until day 57 post-treatment (PT). Oocyst per gram of faeces (OPG) were determined for each animal on the same dates. Mean CLWG and log transformed OPG values were compared within production systems using the Student's t-test. Partial budget analysis was used to evaluate the economic impact of bolus treatment. Untreated animals (P-U and PG-U) showed higher OPG excretion than animals treated with bolus (P-B and PG-B). OPG were reduced in the treated groups of both production systems (P < 0.001), especially in the first 29 days post-treatment. PG-B lambs showed higher CLWG than PG-U lambs (P < 0.05). CLWG of P-U and P-B lambs were similar. Bolus treatment was economically feasible in both systems (PG-B: 1.78USD/animalandP−B:1.78 USD/animal and P-B: 1.78USD/animalandP−B:0.11 USD/animal). Intra-ruminal SMZ boluses reduced excretion of Eimeria OPG in P-B and PG-B groups; however, CLWG was only improved in PG-B lambs.
International journal for parasitology. Drugs and drug resistance, 2018
Ovine Eimeria spp. infections cause reduced welfare, increased mortality, and substantial economic losses, and anticoccidials are crucial for their control. Recent reports of toltrazuril resistance in pigs, and anecdotal reports of reduced anticoccidial efficacy in lambs, necessitate evaluation of anticoccidial efficacy. Due to the substantial lifecycle differences between nematodes and coccidia, current WAAVP methods for assessing anthelmintic efficacy are not suitable for such evaluations. Faecal samples were collected from 8 pairs of twin lambs from 36 Norwegian sheep farms 6-8 days after turnout. One twin of each pair was then treated with 20 mg/kg toltrazuril and a second faecal sample from all lambs was collected 7-11 days later. Oocyst excretion rate in all samples was determined using McMasters. Suitability of treatment timing was investigated by evaluating the increase in mean log oocyst excretion in untreated lambs. Based on comparisons between groups, a threshold of ≥0.75...
Small Ruminant Research, 2006
This trial determined the effect of a sustained-release intra-ruminal sodic sulfamethazine (SMZ) bolus on the Eimeria spp. oocyst output and the cumulative live-weight gain (CLWG) of naturally infected lambs in two different production systems (penned and penned-grazing). Forty male Pelibuey lambs (2-2.5 months old), naturally infected with Eimeria spp., were randomly included in four groups of 10 animals at weaning: (a) penned with SMZ bolus treatment (P-B), (b) penned untreated (P-U), (c) penned-grazing with bolus treatment (PG-B), and (d) penned-grazing untreated (PG-U). Treated lambs (P-B and PG-B) were dosed orally on day 0 with a single SMZ bolus (28.5% of SMZ). Lambs in the PG-U and PG-B groups were allowed to graze 10 h/day. Faecal samples and live-weights were obtained from each lamb on days 0, 8 and every 7 days until day 57 post-treatment (PT). Oocyst per gram of faeces (OPG) were determined for each animal on the same dates. Mean CLWG and log transformed OPG values were compared within production systems using the Student's t-test. Partial budget analysis was used to evaluate the economic impact of bolus treatment. Untreated animals (P-U and PG-U) showed higher OPG excretion than animals treated with bolus (P-B and PG-B). OPG were reduced in the treated groups of both production systems (P < 0.001), especially in the first 29 days post-treatment. PG-B lambs showed higher CLWG than PG-U lambs (P < 0.05). CLWG of P-U and P-B lambs were similar. Bolus treatment was economically feasible in both systems (PG-B: 1.78USD/animalandP−B:1.78 USD/animal and P-B: 1.78USD/animalandP−B:0.11 USD/animal). Intra-ruminal SMZ boluses reduced excretion of Eimeria OPG in P-B and PG-B groups; however, CLWG was only improved in PG-B lambs.
Controlled efficacy trial confirming toltrazuril resistance in a field isolate of ovine Eimeria spp
Parasites & vectors, 2018
Coccidiosis due to Eimeria spp. infections in lambs causes increased mortality and substantial production losses, and anticoccidials are important for control of the infection. Anticoccidial resistance has been reported in poultry and swine, and we recently described reduced toltrazuril efficacy in ovine Eimeria spp. in some Norwegian sheep farms using a newly developed faecal oocyst count reduction test (FOCRT). The aim of the present study was to use a controlled efficacy trial to assess the efficacy of toltrazuril against a field isolate suspected of being resistant. Twenty lambs, 17-22 days old and raised protected against exposure to coccidia, were infected with a field isolate of 100,000 Eimeria spp. oocysts. This isolate was obtained from a farm with a previously calculated drug efficacy of 56% (95% confidence interval: -433.9 to 96.6%). At day 7 post-infection, 10 of the lambs were orally treated with 20 mg/kg toltrazuril (Baycox Sheep vet., Bayer Animal Health), while the o...
Parasitology Research, 2011
16 calves were each infected with suspensions containing a mixture of approximately 230,000 Eimeria bovis and 70,000 E. zuernii oocysts, which resulted in detection of oocysts in faeces of 12 of 16 calves by day +14 after infection. On day +14 after infection calves were either treated (n = 8) with toltrazuril at 15 mg/kg body weight or with a placebo. Observations were made on the clinical condition, faecal score and liveweight of calves daily from one day post infection (p.i.) until 24 days p.i. when all calves were euthanised and examined post mortem. Samples were collected from ileum and colon for histological, immunohistochemical and gene expression studies. The study demonstrated an efficacy of toltrazuril for the treatment of E. bovis and E. zuernii infections in calves reaching 99 % (based on arithmetic mean oocyst counts in faeces) within three days of treatment and remaining at or above this level for six days. Toltrazuril did not have a significant effect on the pattern and extent of immune cellular infiltration in the mucosa of ileum and colon, but the expression of the genes coding IL-2, IL-10 and TNF-a in the ileum and TNF-a in the colon were elevated in calves treated with toltrazuril. Higher levels of oocyst shedding were significantly associated with lower expression of genes coding for IL-2, IL-10 and higher IP-10. It is concluded that toltrazuril is effective for the treatment of coccidiosis due to E. bovis and E. zuernii in calves and enables the development of a normal or enhanced immune response to infection. S54 S54 ENDoPArAsitEs ENDoPArAsitEs ENDoPArAsitEs S55 S55 ENDoPArAsitEs immunohistochemistry and gene expression of cytokines and chemokines.