Specific Veterinary Drug Residues of Concern in Meat Production

Abstract

A broad variety of veterinary drugs are used in livestock and they could therefore appear as residues in meat and edible tissues for human consumption. Antibiotics to treat bacterial infections, anthelmintics to control parasites, and β-agonists as growth-promoting agents have been reported as some of the most commonly used drugs. The amount, frequency, and risk associated with their use and the impact on human health have been the criteria to consider them of special concern in livestock meat production. The main groups of drugs used in “mass medication,” antibacterial (β-lactam, quinolones/fluoroquinolones, aminoglycosides/aminocyclitols, sulfonamides, tetracyclines, macrolides) and antiparasitic/anthelmintic drugs (benzimidazoles, avermectins and milbemycins, levamisol, AADs) are described. The extensive therapeutic, metaphylactic, prophylactic or growth promoter uses of antibiotics have supported the intensification of modern food-animal production. However, a major concern is that inappropriate uses in livestock can generate antibiotic resistance in nonpathogenic bacteria, whose genes are transferred to pathogenic bacteria, resulting in antibiotic-resistant infections for humans. Anthelmintics are drugs used to treat flat (trematodes and cestodes) and round (nematodes) worm infections, a serious and common problem in livestock to such an extent that these drugs are traditionally used in farming. The β-agonist group, used for a long time in the treatment of respiratory diseases and as tocolytics, has been considered regarding its activity as growth promoters in meat production species, phenethanolamine derivatives (ractopamine and zilpaterol) being the most widely used drugs. However, opinions about their effect on meat are controversial: some authors agree on the use of β-agonists to achieve better utilization of food and sensory characteristics of meat, while others disagree because of the adverse consequences of using these substances.