Efficacy of toltrazuril as a metaphylactic and therapeutic treatment of coccidiosis in first–year grazing calves (original) (raw)
Related papers
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.
Preventive veterinary medicine, 2008
We compared the therapeutic effect of three anticoccidial drugs (toltrazuril, sulphadimidine and amprolium) in buffalo (Bubalus bubalis) calves experimentally infected with Eimeria bovis (E. bovis) and E. zuernii oocysts (3 Â 104 oocyst/calf). Buffalo calves (1.5-4 month old, 70-kg body weight) were randomly allocated into 3 groups (9 calves each). Group T was experimentally infected with oocysts and treated with toltrazuril (20 mg/kg BW twice orally at a 1-week interval). Group S was experimentally infected with oocysts and treated with sulphadimidine (125 mg/kg injected IM followed by half dose for 4 successive days). Group A was experimentally infected with oocysts and treated with amprolium (50 mg/kg orally for 7 successive days). Each group had three subgroups (three calves/subgroup) to represent timing of the drug administration: 1st day of coccidia infection (FD), onset of clinical signs of coccidiosis (CC), and onset of oocyst shedding into the faeces (OS). Clinical signs, body-weight gain (BWG) and number of oocysts per gram feces (OPG) were monitored daily for 35 days post-infection (DPI). The OPG were reduced (but the BWG was not different) in the T calves compared to S and A calves. Within the same group, treatment from the 1st day of infection reduced the OPG and increased the BWG compared to the later treatment timings. #
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...
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.
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.
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 International, 2005
Two studies were conducted in the Eimeria zuernii infection model in order to investigate the pathology of E. zuernii coccidiosis and the efficacy of toltrazuril (Baycox 5% suspension) in this infection. For this purpose, a total of 30 calves were infected experimentally with E. zuernii oocysts and faecal samples taken regularly from the rectum and examined for faecal consistency and oocyst excretion. Six of the calves underwent pathological examination at various points in time after infection. Significant macroscopic and microscopic changes were demonstrated and parasitic stages were identified in the intestinal mucosa of infected calves during the late prepatent and patent period. Inflammatory reactions revealed by light microscopy were confirmed by electron microscopical investigations. Treatment of calves with toltrazuril during the late prepatent period resulted in significantly lower frequencies of diarrhoea and levels of oocyst excretion, and weight gain was significantly higher than in shamtreated animals.
Chemotherapy of Coccidiosis in Calves
Archives on Veterinary Science and Technology, 2017
Thirty-Six bovine calves less than three months of age were purchased from the Market and reared under standard manage mental conditions. Prior to start the experiment claves were examined for the presence of endoparasite and treated accordingly. The calves were provided green fodder along with concentrates. After one week of deworming and acclimatization, 36 calves were divided into 6 groups. Group A, B, C, D and E were experimentally infected at the rate of 20000 oocysts of E. bovis Group 1 (Healthy control 1) was kept as healthy control (Non-infected and non-medicated). In present study, efficacy of different chemotherapeutic agents against coccidiosis in cow calves was determined. It was concluded amprolium, lasalocid, sulphaquinoxaline, toltrazuril were very effective in treatment of coccidiosis in calves. Non-significant difference-(P>0.05) was observed in percentage efficacy of all four anti coccidial drugs at day 28 onward, i.e 100% for Amprolim, Sulphaquinoxaline, Toltrazuril and 99% for lasalocid. All the four drugs showed satisfactory results at their recommended dose against coccidiosis in cow calves and no toxic effects were found during and after treatment.
Diclazuril in goat coccidiosis
Coccidiosis is probably the main parasitic disease affecting goat kids around the weaning period, leading to high economic losses in goat production due to deaths and delayed growth rates of infected animals. A total of 101 kids of 2-4 weeks of age, naturally infected with Eimeria spp., were divided into five groups and studies were conducted to analyse the effects of metaphylactic administration of diclazuril (Vecoxan®) on parasitological and productive parameters. Two different doses of diclazuril (1 and 2 mg/kg BW, p.o.) were given either at 3 weeks (single treatment) or at 3 and 5 weeks of life (double treatment). The faecal oocyst shedding and the body weights of the animals were monitored at 2-weeks intervals for 6 consecutive weeks. Treatments of goat kids with diclazuril were effective against the three most predominant Eimeria species recorded in this study (E. arloingi, E. ninakohlyakimovae and E. christenseni) and also against other minor species found in faecal examinations, including E. alijevi, E. caprina, E. jolchijevi, E. caprovina, E. hirci and E. aspheronica). In consequence, OPG values lower than 1×10 3 were detected in 90 to 100% of the animals up to 15-20 days post-treatment depending on the treatment regimen. Even a single dose of 1 mg/kg BW p.o. resulted in an increase of growth rates in treated animals and therefore should be considered as a control strategy in farms precluding coccidian infections, whilst double and multiple dose treatments could be the recommendation for environments heavily contaminated with Eimeria oocysts. In relation to the OPG reduction and increased growth rates, the severity of the clinical signs (i.e., diarrhoea) was ameliorated in treated animals during the course of infection compared to that of non-treated or control kids. The precise timing of treatment appears crucial in order to prevent severe clinical coccidiosis and thereby enabling the adequate development of protective immune response against Eimeria challenge infections.