Study On Toxicities And Residues Of Toltrazuril

Fowl Globidiosis pertains to a kind of cytozoon disease caused by Eimeria tenella and mainly occurs in three months especially from 15 months to 45 months, leading to 70 percent disease incidence, death rate ranging from 20 percent to 50 percent and 2 billion dollor loss every year. Nowadays, fowl globidiosis was mainly treated by drugs, which pharmacodynamic action was cut down as the birth of new coccidian strain. It was urgent to develop the anti-coccidian drug possessing the characteristic of high performance, least toxicity and difficult to form drug resistance.Experimental researchs including curative effect, toxicity and residual of toltrazuril produced by shanghai xinya Co.Ltd in order to provide certain theory and experiment foundation for veterinary practice and food sanitation.Clinical curative effect was determined by clinical symptom, disease incidence,mortalit, relative growth rate, excrement and urine score, pathological change score, oosphere etc, and gained anti-coccidian index by Merck method.Different group of rats were treated by intragastric administration and meanwhile control group was prepared.The results showed that median lethal dose(LD50) of toltrazuril was 4645mg/kg and 95% confidence interval ranged from 4358mg/kgto 4950mg/kg.Toltrazuril was a kind of least toxicity drug according to acute toxic ranking standard.Toltrazuril residual was determined by high efficiency liquid chromatography after extracting from fowl liver, kidney and muscle (acetonitrile and acetoacetate, 3/2v/v).The results showed that drug holiday of 100 mg/kg and 50 mg/kg toltrazuril were respectively 14 days and 7 days, which conformed to safe animal medicine standard enacted by Ministry of Agriculture(from 75mg/kg to 100mg/kg).These experimental results demonstrates that toltrazuril has the feature of high performance, least toxicity and difficult to form drug resistance and would be new anti-coccidian drug in future .