The aims of this study were to compare the pharmacokinetics of albendazole sulfoxide (ABZ-SO, ricobendazole) in goats and sheep at a dose of 5 mg/kg bodyweight (BW), after intravenous (IV) and subcutaneous (SC) administrations, and to investigate the effects of increased doses (10 and 15 mg/kg BW) on the plasma disposition of ABZ-SO in goats following SC administration. A total of 16 goats (Capra aegagrus hircus, eight males and eight females) and 8 sheep (Ovis aries, four males and four females) 12–16 months old and weighing 20–32 kg, were used. The study was designed according to two-phase crossover study protocol. In Phase-1, eight sheep were assigned as Group I and 16 goats were allocated into two groups (Group II and Group III). ABZ-SO was applied to Group I (sheep) and Group II (goats) animals subcutaneously, and to Group III (goats) animals intravenously, all at a dose rate of 5 mg/kg BW. In Phase-2, the sheep in the Group I received ABZ-SO intravenously in a dose of 5 mg/kg BW; the goats in Group II and Group III received ABZ-SO subcutaneously at a dose of 10 mg/kg and 15 mg/kg BW, respectively. Blood samples were collected from the jugular vein at different times between 1 and 120 h after drug administrations. The plasma concentrations of ABZ-SO and its metabolites were analysed by high performance liquid chromatography. In goats, the area under the curve, terminal half-life and plasma persistence of ABZ-SO were significantly smaller and shorter, respectively, compared with those observed in sheep following both IV and SC administrations at a dose of 5 mg/kg BW. On the other side, dose-dependent plasma dispositions of ABZ-SO were observed following SC administration at increased doses (10 and 15 mg/kg) in goats. Consequently, ABZ-SO might be used at higher doses to provide higher plasma concentration and thus to achieve greater efficacy against the target parasites.

In this study, it was aimed to demonstrate the possible oxidative stress caused by exposure of xylene and formaldehyde (HCHO) on liver tissue, and on body and liver weights in adult as well as developing rats. The rats (96 female Sprague-Dawley) were randomly divided into four groups: embryonic day 1 (Group 1), 1-day-old infantile rats (Group 2), 4- week-old rats (Group 3) and adult rats (Group 4). The animals were exposed to gases of technical xylene (300 ppm), HCHO (6 ppm) or technical xylene + HCHO (150 ppm + 3 ppm), 8 hours per day for 6 weeks. Superoxide dismutase (SOD) and catalase (CAT) activities, and glutathione (GSH) and malondialdehyde (MDA) levels were evaluated. In addition, body and liver weights were determinated. Compared to the control animals, body and liver weights were decreased in the embryonic day 1 group (P<0.001, P<0.01, respectively) and the 1-day-old infantile group (P<0.001). Liver weight was increased in the 4-week-old group (P<0.01). SOD activities were decreased in the 4-week-old rats exposed to HCHO (P<0.01). CAT activities increased in the embryonic day 1 group (P<0.05). GSH levels were decreased in the 1-day-old infantile group (P<0.01), and MDA levels was increased in the embryonic day 1 group (P0.05). The present study indicates that exposures to xylene, HCHO and a mixture of them are toxic to liver tissue, and developing female rats are especially more adversely affected. Furthermore, the results of this study show that adult female rats could better tolerate the adverse effects of these toxic gases.

The aim of this study was to demonstrate the presence of Flavobacterium psychrophilum in the west Aegean region of Turkey and to evaluate the in vitro susceptibility of F. psychrophilum (isolated from the fry of rainbow trout Oncorhynchus mykiss) to seven antimicrobial agents, as determined by the disk diffusion and agar dilution methods. A total of 250 rainbow trout fry (weight = 2–5 g; total length = 3–6 cm) were examined, and 20 bacterial isolates were phenotypically identified. Antimicrobial agents included in this investigation were amoxicillin–clavulanic acid (AMC), erythromycin (E), enrofloxacin (ENR), florfenicol (FFC), gentamicin (CN), oxytetracycline (OT), and sulfamethoxazole–trimethoprim (SXT). Disk diffusion and agar dilution methods were performed according to published standards. Minimum inhibitory concentration (MIC) ranges were determined using the agar dilution method for F. psychrophilum isolates. Resistance of F. psychrophilum to CN (disk diffusion method: 70%; agar dilution method: 95%), E (65%; 100%), and SXT (75%; 100%) was high using both methods. Resistance to ENR (10%; 15%) and FFC (25%; 25%) was low with both methods; MIC₉₀ (minimum concentration required to inhibit bacterial growth by 90%) was 4 μg/mL for ENR and 16 μg/mL for FFC. Ninety percent of the F. psychrophilum isolates were resistant to AMC based on the disk diffusion method, while only 15% of isolates showed resistance based on the agar dilution method. For OT, 20% of isolates were resistant based on disk diffusion, while 75% exhibited resistance based on agar dilution. The importance of susceptibility testing when facing an outbreak of F. psychrophilum at a fish farm is obvious; however, the discrepancies between testing methods for AMC and OT require further studies.

AIMS: To determine the plasma disposition of meloxicam in goats following S/C, oral or I/V administration at a single dose of 0.5 mg/kg bodyweight. METHODS: Five healthy Saanen goats, aged 12–14 months and weighing 35–40 kg, were used for a three phase cross-over design with a 10-day washout period, with meloxicam administered I/V, then orally and S/C. Heparinised blood samples (5 mL) were collected from all animals prior to drug administration (0 hours) and subsequently up to 96 hours. Concentrations of meloxicam in plasma were measured using high performance liquid chromatography. Concentration-time curves were fitted and pharmacokinetic parameters were estimated for each administration group. RESULTS: Subcutaneous administration of meloxicam exhibited unique plasma distribution characteristics that differed from oral and I/V administration. Mean peak plasma concentrations were greater (1.91 (SD 0.39) vs. 0.71 (SD 0.17) µg/mL) and the time to reach them shorter (3.20 (SD 1.64) vs. 14.33 (SD 2.19) hours) following S/C compared with oral administration (p<0.05). The terminal half-life was longer (15.16 (SD 4.74) vs. 10.69 (SD 1.49) hours) and the MRT was shorter (15.67 (SD 2.37) vs. 24.33 (SD 3.12) hours) following S/C than oral administration (p<0.05), but bioavailability was similar (98.24 (SD 9.62) vs. 96.49 (SD 10.71)%). CONCLUSION AND CLINICAL RELEVANCE: Subcutaneous administration of meloxicam resulted in long-term presence of drug at high concentration in goat plasma. This unique plasma disposition characteristic may offer an advantage in some clinical cases towards potentially improving the treatment efficacy in goats.