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The objective of this study was to assess the impact of the vehicle of administration and the prandial state of post weaning piglets on the indices of therapeutic efficacy for different broad‐spectrum antibiotic/pathogen combinations. Pharmacokinetic data were retrieved from previous studies, in which we orally administered oxytetracycline (OTC), fosfomycin (FOS), or amoxicillin (AMX) according to the following treatments: dissolved in soft water to fasted or non‐fasted piglets, dissolved in hard water to fasted or non‐fasted piglets, and mixed with feed. Minimum inhibitory concentration (MIC) values for susceptible strains of bacteria causing swine diseases were obtained from the database of European Committee on Antimicrobial Susceptibility Testing (EUCAST) for each antibiotic. Pharmacokinetic/pharmacodynamic (PK/PD) indices of therapeutic efficacy—drug exposure over the dosing interval (fAUC/MIC) for OTC and FOS; time that free drug concentration remains above MIC (%fT>MIC) for AMX—were calculated for each antibiotic/pathogen combination under each treatment. After all OTC and in‐feed FOS and AMX treatments, the indices of therapeutic efficacy were below the target value for all the study microorganisms. When FOS or AMX were delivered dissolved in soft or hard water, the indices were above the target value over which therapeutic efficacy would be expected for Escherichia coli treated with FOS and, Glaesserella parasuis, Pasteurella multocida, and Actinobacillus pleuropneumoniae treated with AMX. The prandial state of piglets showed no influence on the indices of therapeutic efficacy. Pharmacokinetic profiles of broad‐spectrum antibiotics, specifically the ability to achieve target concentrations, may be largely reduced due to drug interactions with components present in feed or water resulting in a discrepancy with PK/PD principles of prudent and responsible use of antibiotics. [ABSTRACT FROM AUTHOR]

Due to the lack of drugs regulated for aquaculture, we have evaluated the use of albendazole (ABZ) – a potential drug to be regulated for fish – under food safety perspectives assessing the depletion profile of ABZ and its main metabolites (albendazole sulphoxide – ABZSO, albendazole sulphone – ABZSO2 and albendazole amino sulphone – ABZ-2-NH2SO2) in fish fillets (muscle and skin) after single dose oral administration of 10 mg ABZ kg-1 body weight. For the drug administration, a suitable procedure for ABZ incorporation into fish feed was employed, obtaining good homogeneity of ABZ concentration among feed pellets (CV<4.1%) and low drug leaching when medicated feed remained in the water for up to 60 min (<2.7%). After medication, fish were euthanised at 8, 12, 24, 48, 72, 96 and 120 h and fillets collected. Depletion studies in various fish species (patinga and tilapia) were conducted simultaneously, under water temperature at 30.4 ± 0.3 °C and pH 6.8 ± 0.1. The highest concentrations for the sum of residues (ABZ, ABZSO, ABZSO2 and ABZ-2-NH2SO2) in fish fillet were 1210 ng g-1 in patinga and 637 ng g−1 in tilapia. Under the employed rearing conditions, the obtained results did not indicate a requirement for a minimum withdrawal period to be proposed for tilapia considering the maximum residue limit of 100 µg g−1, since the determined residual concentration was

Circadian variation of serum concentrations of tylosin in broiler chickens after in-feed medication prompted a comparison study of the serum profiles of this drug after in-feed medication with standard tylosin phosphate (Tprf reference formulation group), and after infeed medication with a sustained-release pellet formulation (Tpsr group), based on Patent No.MX/a/2012/013222 and PCT/MX2013/000137, in broiler chickens. Six hundred 4-weekold Ross broiler chickens were in-feed medicated with tylosin phosphate at an approximate dose of 25.2 mg/kg/d, based on daily feed consumption values and a final concentration of tylosin in feed of 200 mg/kg of feed.Approximately 2 to 3mL of bloodwere obtained per 5 chickens every 2 h, avoiding the sampling of a bird more than once and during 72 h after making medicated feed available for the first time. Serum concentrations of tylosin were determined by HPLC. Gaussian multi-peak regressions were then fitted to serum concentration vs. time profiles. Day by d areas under the serumconcentration vs. time profiles (AUC0-24), as well as overallAUC0-72, were statistically higher for the Tpsr group (P < 0.001). Also, maximum serum concentrations obtained and relative bioavailability for the Tpsr formulation were statistically higher (382.8%) as compared to the Tprf group (P < 0.01). Considering the referred improved values of AUC observed in the Tpsr formulation, aswell as the fact that tylosin is a time-dependent antibacterial drug, better clinical responses are postulated with this pharmaceutical preparation intended for chickens. Tissue deposition studies for this new formulation of tylosin are required. [ABSTRACT FROM AUTHOR]

As infecções intestinais por espiroquetas em suínos, na fase que se segue ao alojamento nos prédios de recria, são predispostas por fatores como o estresse da movimentação, mistura entre animais imunes e excretores com leitões não imunes, deficiências nas condições ambientais e troca no tipo da ração usada. Para contrabalançar esses efeitos, é uma prática rotineira a inclusão de antimicrobianos à ração, em doses de promoção de crescimento ou de controle. O presente trabalho avaliou a ocorrência da infecção por Brachyspira spp. em rebanhos suínos do Estado do Rio Grande do Sul, tentando relacionar com o tipo de programa de uso de antimicrobianos adotado. Foram examinados 393 suabes retais colhidos de 38 granjas do RS (22 usando rações medicadas e 16 com ração sem medicação). A B. hyodysenteriae e B. pilosicoli foram detectadas respectivamente em 0% e 6,25% das granjas medicadas e de 31,8% e 45,5% das granjas não medicadas. Entre os suabes examinados, a B. hyodysenteriae e B. pilosicoli estavam presentes respectivamente em 0 e 0,6% dos materiais colhidos de granjas medicadas e de 3,9% e 7,3% em granjas não medicadas. O presente trabalho suporta a opinião de diversos autores que sugeriram a influência direta da inclusão de antimicrobianos à ração em doses de promoção de crescimento ou em dose de controle e a ocorrência de diarréias espiroquetais em leitões. Entretanto, pelas características multifatoriais desse tipo de patologia, seriam necessários estudos adicionais abrangendo um número maior de variáveis entre aquelas possivelmente envolvidas no desencadeamento das diarréias, antes que fosse obtida uma conclusão definitiva.Intestinal spirochaetal infections in pigs following transportation to growing facilities is predisposed by stressful factors such as contact between carriers and non-immune piglets, defficient environment and diet changes. To neutralize such effects, it is a common practice to include antimicrobials to feed in promoting or control levels. The present work assessed the occurrence of Brachyspira infection in pig herds in the State of Rio Grande do Sul, Brazil, trying to relate the infection with the feed medication program. A total of 393 rectal swabs collected from 38 farms were bacteriologically examined (22 from farms using medicated feed and 16 with non-medicated feed). B. hyodysenteriae and B. pilosicoli were isolated respectively from 0% and 6,25% in medicated herds and from 31.8% and 45.5% in non-medicated farms. B. hyodysenteriae and B. pilosicoli were isolated respectively from 0% and 0.6% swabs collected in medicated farms and from 3.9% and 7.3% swabs from non-medicated farms. The present work agrees with several authors who suggest a direct influence of inclusion of antimicrobials to feed in promotion on growth levels on spirochaetal diarrhoea in pigs. However, considering the multifactorial determination of this condition, additional studies investigating the importance of other variables would be necessary to reach a definitive conclusion about the role of medication in the determination of diarrhoea caused by pathogenic spirochetes.

Drugs can be administered to birds either individually or as a flock treatment. For poultry, drinking water and feed medication are preferred, but in the case of serious disease, parenteral administration can be an alternative. For an efficient and safe therapy, data on drug pharmacodynamics and pharmacokinetics are required. Therefore, the gastrointestinal anatomy and physiology of birds, and the elimination of drugs in birds are discussed in this review. In addition, important aspects of drinking water medication, such as water quality, individual water uptake, drinking water system, lighting periods and drug formulations are discussed. Also, some requirements concerning feed medication are mentioned. Finally, parenteral and vaccine administration in the poultry industry are described. [Copyright &y& Elsevier]