Survey on antimicrobial prescribing patterns in small animal veterinary practice in Emilia Romagna, Italy.

This investigation provides for the first time a general view of the prescribing patterns of antimicrobials in small animal practice in Emilia Romagna, Italy. In the context of a project on antimicrobial resistance managed by the Regional Veterinary Service, veterinary clinicians were invited to voluntarily complete an online questionnaire. This was designed to gather information on antimicrobial prescribing practices and biosecurity measures and to understand the perception of the issue specific to this region of Italy. In total, 266 questionnaires correctly completed were collected. Although clinicians seemed to follow different approaches when using antimicrobials, the data analysis revealed a general awareness on resistance. Penicillins were the most commonly prescribed class, followed by (fluoro)quinolones and cephalosporins. Among those who use laboratory testing more or less frequently (microbiological analysis and susceptibility testing) to support their prescribing habits, only 7 per cent make a habit of always waiting for the results before starting the treatment. Seventy-eight per cent of the respondents declared the use of antimicrobials licensed for human beings. Biosecurity measures were carefully taken into account by the majority of the veterinarians. The results identified the antimicrobial classes that are commonly prescribed and highlighted that perioperative hygiene measures and the use of laboratory diagnosis are critical aspects that need to be emphasised in drawing up guidelines on the prudent use of these drugs in pets.

The use of fentanyl-patch in dogs undergoing spinal surgery: plasma concentration and analgesic efficacy.

Objectives of this study were to evaluate plasma concentrations and analgesic efficacy of fentanyl administered transdermically in dogs undergoing spinal surgery. At the end of the surgery and before awakening, a fentanyl-patch was applied and was maintained in situ for 72 h. Blood samples were taken before the application of the patch, at 2, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48, 60, and 72 h after application and then 2, 4, 6, 8, 10, and 12 h after its removal. Before each blood sampling, pain evaluation was carried out using the Glasgow pain score, appropriately modified. Plasma concentrations of fentanyl were determined using a specific immuno-enzymatic kit. In this study, the minimum analgesic plasma concentration (0.23 ng/mL) required to achieve analgesia in human and considered to apply also for dogs was reached in all animals. No animal showed pain in the range of 'intense pain'; in two cases, the level of the pain was slight or moderate. No undesired effects were found. Results suggest that the use of transdermic patches could represent a valid aid in pain therapy in small animals; in particular, it contributes to the postoperative well-being of patients undergoing major surgery.

A clonal cell line (BME-UV1) as a possible model to study bovine mammary epithelial metabolism: metabolism and cytotoxicity of aflatoxin B1.

Despite the toxicological risks to which humans and animals are exposed due to the transfer of toxic xenobiotic metabolites into milk of domestic animals, studies on the metabolizing mechanisms occurring in ruminant mammary gland are totally lacking. To investigate the possible biotransformation capabilities of a bovine mammary epithelial cell line (BME-UV1), monolayers were exposed to aflatoxin B1 (AFB1--1.0-8.0 microM). Starting from 4 h of exposure, the hydroxylate metabolite aflatoxin M1 (AFM1) was detected in media by high performance liquid chromatography. AFM1 concentration increased linearly with time for 36-48 h and the percent biotransformation of AFB1 (2-4 microM) at 48 h was about 12-14%. Parallel cytotoxicity assays (neutral red uptake-NRU and MTT assays) were performed to investigate the possible interference of AFB1 cytotoxicity with cellular metabolism. MTT assay (from 24 h of cell exposure) and NRU assay (from 16 h of cell exposure) showed time-dependent and time/concentration-dependent decrease of cell viability, respectively, and the former assay being more successful at revealing cytotoxic effects (NRU: CC50 at 48 h = 12.00 +/- 2.66 microM; MTT: CC50 at 72 h = 20.42 +/- 7.30 microM). The results suggest that BME-UV1 cells express metabolizing enzymes having catalytic activity, thus representing a potential in vitro model for studying biotransformation in bovine mammary gland.

Investigation of the metabolic activity of a bovine mammary epithelial cell line (BME-UV1).

The metabolic activity of a mammary epithelial cell line (BME-UV1) was evaluated on monolayers exposed, in serum free medium, to different concentrations (2-4-8 muM) of aflatoxin B1 (AFB1), a mycotoxin eliminated into milk especially as hydroxylated metabolite aflatoxin M1 (AFM1). After 4, 8, 12, 24 h of treatment, a dose and time dependent production of AFM1 has been detected. As the enzymes involved in the hydroxylation of AFB1 in bovine hepatocytes are mainly CYP1A and CYP3A, the results suggest that BME-UV1 express CYP450 isoenzymes which metabolize AFB1 thus representing a potential model for the investigation of the metabolic activity of bovine mammary epithelial tissue.

Mannanoligosaccharides and aflatoxin B1 in feed for laying hens: effects on egg quality, aflatoxins B1 and M1 residues in eggs, and aflatoxin B1 levels in liver.

Ninety-six laying hens were allocated to 4 groups and fed diets (control diet (0-0), diet supplemented with 2.5 ppm aflatoxin B1 (0-AF); diet supplemented with 0.11% mannanoligosaccharide (MOS-0); diet supplemented with 0.11% MOS and 2.5 ppm aflatoxin B1 (MOS-AF) for 4 wk to evaluate the effect of aflatoxin B1 (AFB1), mannanoligosaccharide (MOS), or both on egg quality and the in vivo efficacy of MOS to interact with an oral administration of AFB1. After 2 and 3 wk, egg weight decreased (P < 0.05) in the group fed MOS-0 versus groups on 0-0 and 0-AF. Egg shell weight was lower (P < 0.05) in the group fed 0-AF. Aflatoxin influenced color parameters, which were probably related to interference of AFB1 with lipid metabolism and pigmentary substances deposition in yolk. MOS appeared to increase protein percentage in albumen. No AFB1 or aflatoxin M1 (AFM1; a polar metabolite of AFB1) residues were found in eggs of the experimental groups. Livers from groups 0-0 and MOS-0 always tested negative for AFB1 and AFM1. Differences (P < 0.01) were found between AFB1 hepatic levels of group 0-AF (mean +/- SD: 4.13 +/- 1.95 ppb) and group MOS-AF (mean +/- SD: 2.21 +/- 1.37 ppb). The data demonstrated the ability of MOS to adsorb and degrade AFB1, reducing gastrointestinal absorption of AFB1 and its levels in tissues.

Aflatoxin B1 and clinoptilolite in feed for laying hens: effects on egg quality, mycotoxin residues in livers, and hepatic mixed-function oxygenase activities.

Ninety-six laying hens were allocated to four groups administered different diets (group 0-0 received a complete diet, group 0-AF received a diet supplemented with 2.5 ppm of aflatoxin B1 [AFB1], group 2-0 received a diet supplemented with 2% clinoptilolite [CPL], and group 2-AF received a diet supplemented with 2% CPL and 2.5 ppm of AFB1) for 4 weeks to evaluate the effect of AFBI and/or CPL on egg quality and the ability of CPL to interact with the oral administration of AFB1. The possible effects of AFB1 on cytochrome P450-dependent hepatic mixed-function oxygenase (MFO) activities were also evaluated. Mycotoxin reduced yolk weight, while CPL influenced albumen percentage relative to that of eggs laid by chickens in group 0-AF Eggs laid by chickens in groups 0-AF and 2-AF had stronger shells and weighed less than the eggs of other groups. The eggs of treated groups were lighter in color than those of the control group (P < 0.01), and the tendency to yellowness in eggs was increased by CPL, probably through the affinity of red pigments for adsorbents and a consequent prevalence of yellow tonality. Color parameters might be connected with AFB1's interference with lipid metabolism and pigment deposition. The livers of hens in groups 0-AF and 2-AF showed very low mycotoxin concentrations that were significantly different (P < 0.01). The highest levels observed were those in the livers of the hens receiving the diet supplemented with the mycotoxin alone. AFB1 did not exert any significant effects on the hepatic MFO activities examined.

Relative oral bioavailability of microgranulated amoxicillin in pigs.

A new microgranulated formulation of amoxicillin trihydrate for in-feed medication was developed using a lipogelled matrix. Its relative bioavailability was compared with powdered drug in pigs and an assessment was made to determine whether therapeutic concentrations were achieved. Microgranules containing 10% (MICR10) and 30% (MICR30) amoxicillin and free amoxicillin trihydrate powder (reference, AMX) were administered at dosages of 50 mg of amoxicillin/kg b.w. using a three-way-crossover design. Amoxicillin analysis in serum was performed by a sensitive high performance liquid chromatography (HPLC) method with fluorometric detection, using an extraction procedure already described for edible tissues of fish and adapted and validated for pig serum. The oral bioavailability of both microgranulated formulations was higher than that of the reference formulation [relative bioavailability (F): 153.9 +/- 58.2% for MICR10; 126.2 +/- 70.5% for MICR30] and the area under the concentration-time curve (AUC) values of MICR10 and AMX formulations were significantly different (P < 0.05). Differences between the mean maximum concentration (Cmax), time of Cmax (tmax) and mean residence time (MRT) of the drug formulations were not significant. Microgranulated amoxicillin is suitable for in-feed administration to pigs and, because of its higher oral bioavailability compared with the powdered compound, it may be more effective for the treatment of susceptible infections.

Disposition of antimony and aminosidine combination after multiple subcutaneous injections in dogs.

The disposition of a combination of antimony (Sbv) (12.8 mg/kg) and aminosidine (AM) (10 mg/kg) in 10 healthy Beagle dogs after multiple subcutaneous injections is described. Sbvplasma concentrations were determined by atomic absorption spectrometry, and AM by ion-pair liquid chromatography, using a fluorimetric detector. Sbvreached Cmaxat 60 min, and for about 1 h plasma levels were homogeneously stabilized between 10.78 and 11.76 microgram/mL; by 12 h, Sbvplasma concentrations were close to the detection limit (0.3 microgram/mL). AM Cmaxvalues were recorded after 1 h (30.6+/-3.11 microgram/mL, mean +/- SD), and plasma levels reached values close to the detection limit (0.15 microgram/mL) between 7 and 8 h after injection. Sbvkinetic parameters did not appear modified by the presence of AM. Moreover, repeated injections of the combination did not modify the kinetic behaviour of the two drugs and did not alter the renal function of the animals. The superimposition analysis of the Sbvdata suggests that a twice daily injection of the metal at a dose of 12.8 mg/kg would be sufficient to maintain inhibitory Sbvconcentrations similar to those recorded in humans.

Carbaryl distribution in rabbit tissues and body fluids.

After single po administration of 14C-naphthylcarbamate, liquid scintillation assays evaluated the distribution of carbaryl in rabbit serum, liver, kidneys, small and large intestine, spleen, heart, muscles of the thigh and lungs and its excretion in urine and feces at 2, 4, 6 and 8 h after dosing. At 2 and 8 h radioactivity was not observed in spleen, heart, muscle and lungs, while all other tissues had increased values up to 6 h. The main excretory pathway of carbaryl was the kidneys.