Federal surveillance of veterinary drugs and chemical residues (with recent data)

The National Residue Program is a dynamic risk-based program involving many Federal agencies, with the objective of preventing illegal drug residues and chemicals in the food supply. Surveillance is the systematic collection, analysis, and interpretation of residue data for public health action. This consists of assessing the cause(s) of the problem, recommending educational incentives, and intervention of prevention and control measures. The role of residue databases in formulating policy decisions and identifying risk factors for drug residues is discussed. A descriptive analysis, of 5 years (1992-1996) field investigative reports of drug residue occurrence in food animals is presented. The results showed that violative residues occurred predominately in culled dairy cows and bob veal calves.

The national milk safety program and drug residues in milk

There are a number of factors that must be considered in any attempt to control animal drug residues in milk and milk products. Dairy herds vary greatly in number of cows. Milk from individual cows and farms is pooled, diluting drug residues that may be present in the milk from a single treated cow. Management techniques, including the handling, administration, and record keeping of animal drugs, vary greatly from one dairy to another. It is important that both veterinarians and nonveterinarians adhere to adequate milk discard times for animal drugs used to treat dairy animals. Observance of appropriate safeguards at the farm level, such as record keeping and clearly identifying treated animals, is critical for controlling and preventing the presence of illegal animal drug residues. Within the framework of the Federal Food, Drug, and Cosmetic Act and the Public Health Service Act, the FDA is working with state and other regulatory agencies and industry to better ensure the absence of illegal animal drug residues in milk and milk products. Preventive measures concentrate on minimizing the need to administer animal drugs to lactating cows, and diverting milk containing drug residues from the human food supply. Monitoring programs concentrate on screening milk and tracing violations to the individual producer. Minimizing illegal drug residues in milk and milk products requires close cooperation between farmers, veterinarians, the dairy industry, the pharmaceutical industry, and regulators.

Center for Veterinary Medicine's perspective on the beef hormone case

Steroidal sex hormones and synthetic derivatives are used in the US to enhance growth in food-producing animals. The European Economic Community has banned use of these same substances, reportedly on the grounds of food safety. The US maintains that this ban was and is a disguised restriction on trade. The technical grounds for bringing this case and the impact of the findings of the World Trade Organization on the regulation of animal drugs in the US is discussed.

The Food Animal Residue Avoidance Databank (FARAD). Past, present and future

During the last one-and-one-half decades, FARAD has established an unparalleled compilation of residue and pharmacokinetic information for veterinary species. In order to fulfill its mission, FARAD has become as much a research project as an educational one. Pressing problems, such as disease-altered kinetics, minor-species drug use, and industrial contaminants in livestock, require the new methods of analysis FARAD is developing. The data upon which this work is based can be greatly augmented by participation by other nations. In the United States, it was the cooperation of both academic and regulatory organizations that made the success of FARAD possible. Similar international cooperation can facilitate use of the FARAD model in other countries for the economic benefit of all participants, enhancement of food safety, and promotion of animal welfare.

Field trials of investigational new animal drugs

Field trials provide an opportunity to determine the efficacy and safety of drug treatments in a variety of environments and fish stocks that would not be possible or practical in laboratory settings. The steps for executing good field trials are discussed. The University of Idaho coordinates numerous field trials at over 100 hatcheries throughout the Pacific northwest as part of an intensive and extensive program to register erythromycin injectable and feed additive to control bacterial kidney disease in salmonids. A standardized toxicity test conducted at 52 hatcheries following the completion of administration of erythromycin feed additive provided a way to compare responses by fish at different times of the year, locations, and among different sizes of fish. Some of these fish were used in an assay to quantify the content of erythromycin in kidney tissue post treatment.

Crisis at the Bureau of Veterinary Drugs

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Currently available insulin preparations for use in the dog and cat

Many insulin preparations are available for use in the diabetic dog or cat. Appropriate selection of an insulin preparation must take into account several factors. These include species of patient, type of diabetes, duration of action of insulin, client preferences, and, sometimes, species of origin of the insulin preparation.

Marketing authorization of veterinary medicinal products in Poland

Opening of the European Agency for the Evaluation of Medicinal Products (EMEA) in London (February 1, 1995) has begun harmonization of international requirements in veterinary drug legislation in the European Union (EU). The main objective of this paper is to introduce the principal rules of veterinary drug registration in Poland, a candidate to membership in the EU. In Poland the basic guideline governing quality, production, marketing, and inspection of medicinal products is "The Pharmaceutical Products, Medical Materials, Pharmacies, Wholesaler Outlets, and Pharmacy Inspection Act, dated October 10, 1991." The detailed rules are given in directives of the Minister of Health or the Minister of Agriculture in case of veterinary medicinal products. Since 1993 licensing of drugs in Poland has become a universal procedure for both human and veterinary products. The common Committee of Drug and Medical Materials Registration, which is under control of the Minister of Health and Social Welfare, ensures that the quality, safety (e.g., maximum residue limits and current FAO/WHO and EEC regulations for products used in food-producing animals are accepted), and efficacy are the criteria for the registration process. During 1994-1996 almost 300 veterinary products (more than 200 from the EU) received marketing authorizations in Poland. All these products were evaluated and registered on a similar basis to those in the European Union.

Contaminants of non-biological origin in foods from animals

The authors provide an overview of non-biological contaminants in foods from animals. These contaminants comprise chemical and physical hazards which may be introduced during animal production, slaughter and processing or packaging. Emphasis in this paper is placed on those residues which are of most interest to Veterinary Services and for which Veterinary Services have responsibility, namely: residues of veterinary drugs, industrial chemicals, heavy metals and pesticides which may be introduced during animal production. The most contentious residues which occur in meat, milk and eggs are antibacterial drugs, hormonal growth promoters and certain pesticides, heavy metals and industrial chemicals. While rare incidents of human disease have been attributed to hazardous levels of these contaminants in milk and meat, residues of chemical contaminants in foods of animal origin are, in general, rarely detected at more than trace levels and consequently are not of major public health concern. Nevertheless, non-biological contaminants continue to be very important with respect to international trade and consumer confidence, and efforts to reduce the incidence of occurrence in foods is warranted. Furthermore, continued monitoring and periodic reassessment of risks posed by these contaminants is needed to detect or anticipate new problems so that appropriate action can be taken in the interests of public safety.

The effect of cooking on veterinary drug residues in food; 5. Oxfendazole

The heat stability of the anthelmintic oxfendazole in water, cooking oil and as incurred residues in cattle liver was investigated. Some evidence of instability was found in boiling water after 3 h. This degradation was associated with the formation of a product which was identified by mass spectrometry as the amine formed by hydrolysis of the carbamate functional group on the oxfendazole molecule. In hot cooking oil at 150 degrees C and 180 degrees C the half-life of oxfendazole was 15 min and 6 min respectively. The amine was also shown to form in oil as the concentration of oxfendazole depleted. The effects of cooking on incurred residues of oxfendazole in cattle liver were inconclusive from this study. Several variable factors were found to be in place including: an unstable equilibrium between oxfendazole, oxfendazole sulphone and fenbendazole in incurred tissue; the overall instability of these compounds in tissue during frozen storage for the duration of the project; the distribution of the residues within the tissue used for the study and the effect of protein binding on extractability of residues from the tissue. It was nevertheless found that: (i) cooking did not destroy residues although it may affect the point of equilibrium between oxfendazole, oxfendazole sulphone, fenbendazole and some other metabolites in incurred tissue; (ii) the amine derivative was not observed in raw incurred tissue; (iii) residues were not evenly distributed in raw incurred tissue; (iv) storage time affected the measured residue concentration either because of losses or protein binding or a combination of both.