Efficacy in Stable Coccidiosis

Clinical Trials: Stable Coccidiosis

The first field study examined the efficacy of Baycox® against natural infection of calves with Eimeria zuernii. A farm with the history of coccidiosis was selected and the investigators carried out a preliminary study to determine the presence of infection on the farm. They established that calves when moved to “K2” housing area, suffered from primarily but not exclusively from Eimeria zuernii infection. Hence study was planned to treat metaphylactically 15 days after arrival in “K2” housing area.
 
The study was carried out in two replicates, each with 36 calves. In each replicate calves were allocated to 3 groups of 12 animals each. One group received treatment with Baycox® 5% at 15mg/kg body weight on day 15 (metaphylaxis), while the other two groups received water (control) or Baycox® at 15mg/kg body weight once the coccidiosis had been diagnosed based on clinical symptoms (therapy). In the first replicate the treatment was given on day 22 and second replicate on day 29 (day of coccidiosis diagnosis in the first replicate was day 22 and in second replicate day 29).

The untreated animals developed significant coccidiosis problems following natural infection with Eimeria zuernii. The animals treated on day 15 (early pre-patent period) showed a significantly lower number of scour days and significantly lower oocyst excretion than the therapeutically treated group and the untreated group. There was also a significant difference between oocyst excretion and scouring days between the therapeutically treated group and the untreated one.

The study confirmed the efficacy of single metaphylactic treatment with Baycox® 5% as an oral suspension, during the pre-patent period against natural infection with Eimeria zuernii. Therapeutic treatment cured the parasitological infection and supported the recovery of the affected animals. However metaphylactic intervention controlled completely the detrimental effects of the disease.

Another clinical trial was a multi-centre randomised, blinded study conducted on five farms with a known coccidial problem in Germany and Czech Republic.

Before the start of the study, epidemiological studies confirmed that the animals suffered from coccidiosis between 3 to 4 weeks after introduction to the housing. During the epidemiological study the animals were found to be suffering from Eimeria bovis and/or Eimeria zuernii. The study was conducted on 212 calves on five farms (on three farms two replicates and on two farms one replicate of the study were run, in all eight independent replicates of the study).

The day the animals were moved into the housing was the the start of exposure to coccidia infection. The animals in each replicate were divided into two groups (treatment with 15 mg Baycox®/kg body weight on day 14 after exposure for one group and treatment with water for control group). Calves were monitored for three weeks after treatment. Throughout the study the assessment of health, body weight, oocyst counts and faecal scores were made.

Natural infection resulted in the development of significant clinical coccidiosis problems in water-treated control group animals. Both the oocyst excretion rate and the duration and severity of coccidia-induced diarrhoea were significantly lower in the treated group than in the untreated group.

The study confirmed the efficacy of a single metaphylactic treatment with Baycox® as a 5% oral suspension during the pre-patent period against natural infection with Eimeria bovis and/or Eimeria zuernii.

(H.-C. Mundt, B. Bangoura, H. Mengel, J. Keidel, A. Daugschies Parasitol Res (2005) 97:S134-S142)