Exposure assessment of anticoagulant rodenticides in the liver of red foxes (Vulpes vulpes) in Slovenia.

The study deals with the environmental residues of anticoagulant rodenticides (ARs) in Slovenia to evaluate the toxicological risk of secondary poisoning of red foxes (Vulpes vulpes) as representatives of non-target wildlife, and in relation to the investigated use patterns of ARs and specific local parameters in Slovenia. From 2019 to 2022, 148 liver tissue samples of adult red foxes were collected from almost all state geographical regions. The samples were extracted with methanol/water (2:1, v/v), cleaned-up using a solid supported liquid-liquid extraction, and measured by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) with reporting limits of 0.

Experimental Exposure to Bisphenol A Has Minimal Effects on Bone Tissue in Growing Rams-A Preliminary Study.

Bisphenol A (BPA) is a well-known synthetic compound that belongs to the group of endocrine-disrupting chemicals. Although bone tissue is a target for these compounds, studies on BPA-related effects on bone morphology in farm animals are limited. In this preliminary study, we investigated the effects of short-term dietary BPA exposure on femoral morphology, metabolism, mineral content, and biomechanical behavior in rams aged 9-12 months.

Bisphenol A in edible tissues of rams exposed to repeated low-level dietary dose by high-performance liquid chromatography with fluorescence detection.

The presented work deals with levels and distribution of bisphenol A (BPA) in the edible tissues of a large food-producing animal species. An experimental animal study included 14 young Istrian pramenka rams (Ovis aries), of which seven were exposed for 64 days to a low dietary dose of BPA at 25 µg/kg b.w.

Basic Exploratory Study of Bisphenol A (BPA) Dietary Administration to Istrian Pramenka Rams and Male Toxicity Investigation.

Bisphenol A (BPA), an endocrine-disrupting chemical and environmental pollutant, has been reported by many researchers to induce male reproductive toxicity in different experimental models. In this study, we investigated whether long-term exposure for two months to 25 µg/kg body weight (low dose) of BPA affects spermatogenesis or sperm quality in young Istrian Pramenka rams exposed via diet. We evaluated body and testicular weights, histopathology of testes and epididymides, and sperm analyses, and compared these parameters between the group of treated rams and the control group of rams.

Seminiferous epithelium cycle staging based on the development of the acrosome in ram testis.

Testicular histopathology is considered the most sensitive and reliable method to detect the effects of chemicals on sperm production. To carry out a sensitive examination of testicular histopathology and interpret the changes require knowledge of spermatogenic stages. Spermatogenic staging based on acrosome development during spermiogenesis is conventionally performed in animal species routinely used for research and toxicity testing.

A rapid analysis of Bisphenol A using MISPE coupled with HPLC-FLD in tissues of food-producing animals.

Bisphenol A (BPA) is a highly-produced organic compound of anthropogenic origin with a wide-range use and is ubiquitously present in both living organisms and the environment. A previously published analytical method for testing of the free (aglycone) BPA in foodstuffs was simplified and optimized for sheep muscle tissue, kidney and liver, by using only a single MISPE purification step allied with HPLC-FLD analysis. The recovery rates and RSD values over a concentration range of 1-10 µg/kg were in the range of 67‒86% and 3‒34%, respectively, while linearity in the matrix, represented by the r, was ≥0.

Sudden outbreak of metastatic intestinal adenocarcinoma in rainbow trout Oncorhynchus mykiss.

Intestinal adenocarcinomas are uncommon in fishes. To date, they have been reported in zebrafish Danio rerio, blue gularis Fundulopanchax sjostedti, koi carp Cyprinus carpio koi, Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss. Metastases are even rarer and have been observed so far at very low prevalence, only in feed-induced adenocarcinoma in Atlantic salmon and rainbow trout.

Determination of free and total bisphenol A in the urine and feces of orally and subcutaneously dosed sheep by high-performance liquid chromatography with fluorescence detection.

An analytical procedure has been introduced to enable a study of the excretion of free bisphenol A (BPA), total BPA and its main metabolite bisphenol A glucuronide (BPA-GLUC). In the experiment, in which 100 μg/kg b. w.

Preliminary toxicokinetic study of BPA in lactating dairy sheep after repeated dietary and subcutaneous administration.

Dietary intake is the predominant route of human exposure to bisphenol A and one of the important food commodities is milk. The aim of our study was to preliminarily evaluate the bisphenol A exposure and disposition in sheep milk after repeated dietary and subcutaneous administration of a relatively low dose (100 µg/kg of b. w.

Analysis and Occurrence of Bisphenol A in Mediterranean Mussels (Mytilus galloprovincialis) Sampled from the Slovenian Coastal Waters of the North Adriatic Sea.

During 2015, a selection of Mediterranean mussels (Mytilus galloprovincialis) and seawater were sampled along the Slovenian coast, which is part of the North Adriatic Sea, in order to test for the presence of bisphenol A (BPA). The concentration of the BPA in the tissues of mussels sampled from the farms and open sea was from < 0.03 to 0.

Recent developments in the analysis of avermectin and milbemycin residues in food safety and the environment.

A review of the developments on the analysis of residues of avermectins and milbemycins (both macrocyclic lactones) is presented. The macrocyclic lactones (MLs) are an important class of chemicals, which are used worldwide as veterinary drugs and as crop protection agents. As a result, residues of MLs are important from both a food safety and environmental perspective.

Influence of P-glycoprotein inhibition on secretion of ivermectin and doramectin by milk in lactating sheep.

The aim of to the present study was to evaluate the effects of verapamil (VER) on plasma pharmacokinetics of ivermectin (IVM) and doramectin (DOR) in lactating Istrian Pramenka dairy sheep and to investigate the role of P-glycoprotein (P-gp) in transport of avermectins into milk. Pharmacokinetics of IVM and DOR following subcutaneous administration of 0.2mg/kg b.

Trace analysis of endectocides in milk by high performance liquid chromatography with fluorescence detection.

An analytical method has been developed for the simultaneous determination of the following endectocide drugs in milk: ivermectin, abamectin, doramectin, moxidectin, eprinomectin, emamectin and nemadectin. Samples were extracted with acetonitrile, purified with solid-phase extraction on a reversed phase C(8), derivatised with N-methylimidazole, trifluoroacetic anhydride and acetic acid to a stable fluorescent derivative, and were further analysed by gradient high performance liquid chromatography (HPLC) on an endcapped reversed phase Supelcosil LC-8-DB. The derivatisation step was mathematically optimised and the method was validated according to the requirements of Commission Decision 2002/657/EC, using fortified raw bovine milk.

Factors influencing dissipation of avermectins in sheep faeces.

Factors influencing fate of avermectins (abamectin, doramectin) in faeces of treated sheep were investigated under different experimental conditions. In the laboratory, concentrations of both avermectins were declined in homogenised faeces of treated animals until day 14 of exposure, regardless of experimental conditions. After that day, no significant decrease in concentrations was observed till the end of the experiment.

Linearity of eprinomectin pharmacokinetics in lactating dairy sheep following pour-on administration: excretion in milk and exposure of suckling lambs.

Pharmacokinetics of eprinomectin (EPR) were studied in blood plasma and milk in two groups of six Istrian Pramenka dairy sheep and their suckling lambs following pour-on administration of EPR to ewes at dose levels of 0.5 and 1mg/kg. Maximum concentration in plasma was 2.

Kinetics of abamectin disposition in blood plasma and milk of lactating dairy sheep and suckling lambs.

Abamectin (ABM) has been used worldwide as an anthelmintic drug in veterinary medicine and as an agricultural pesticide. Its pharmacokinetics and permeation into milk was evaluated in dairy sheep after subcutaneous administration. ABM elimination half-lives and mean residence times were 1.

Determination of residues of azaperone in the kidneys by liquid chromatography with fluorescence detection.

An analytical method has been developed for the quantitative determination of residues of the tranquillizer azaperone (AZN) in the kidneys of slaughtered animals. Samples were extracted with acetonitrile, extracts were acidified and further purified with solid-phase extraction (SPE) on a polymeric mixed-mode cation-exchange sorbent, Oasis. AZN and its main metabolite azaperol (AZL) were eluted by alkaline methanol (MeOH), the eluate was evaporated, re-dissolved and analysed by gradient high performance liquid chromatography (LC) on reversed and deactivated phase LiChrospher 60-RP select B at excitation and emission wavelengths of 245 and 345 nm, respectively.

Analytical procedure for determination of the time profile of eprinomectin excretion in sheep faeces.

An analytical procedure has been introduced to enable study of the time profile of eprinomectin excretion in sheep faeces. Eprinomectin was extracted from sheep faeces with acetonitrile, the extract was cleaned by solid-phase extraction (SPE), and, after derivatization by reaction with N-methylimidazole, trifluoroacetic anhydride, and acetic acid, eprinomectin was analysed by high-performance liquid chromatography (HPLC) with fluorescence detection. The method has a low detection limit (1.

Review of methodology for the determination of macrocyclic lactone residues in biological matrices.

The macrocyclic lactones (MLs) are probably the anti-parasitic agents most widely used in the treatment of food producing animals, poultry, aquaculture and crops. Ivermectin was the first macrocyclic lactone product to be licensed for use about 20 years ago. A number of alternative products such abamectin, doramectin, emamectin, eprinomectin, moxidectin, milbemycin and selamectin, have been marketed since.

Abamectin effects on rainbow trout (Oncorhynchus mykiss).

The effect of abamectin (ABM) on rainbow trout (Oncorhynchus mykiss) was studied. The acute toxicity of ABM on rainbow trout was established, following the target 58-h water bath exposure of ABM concentrations from 0.6 to 4.

Performance characteristics of an analytical procedure for determining chloramphenicol residues in muscle tissue by gas chromatography-electron capture detection.

Validation of an analytical method for determining chloramphenicol residues in muscle tissue by gas chromatography-electron capture detection (GC-ECD) was performed according to the latest European Union criteria for the analysis of veterinary drugs in food, laid down by Commission Decision 2002/657/EC. The method using the meta isomer of chloramphenicol as an internal standard proved to be very selective, specific to other related phenicols and accurate to within +3.6% at a concentration level of 8.

Time profile of abamectin and doramectin excretion and degradation in sheep faeces.

We studied abamectin and doramectin excretion and their degradation in sheep faeces under field conditions on pasture after a single subcutaneous dose (0.2mg/kg body weight). In the excretion experiment, maximal abamectin concentration (1277 ng/g dry faeces) was detected on day 3, while doramectin concentration showed two peaks (2186 and 1780 ng/g dry faeces on days 2 and 5, respectively).

Degradation of abamectin and doramectin on sheep grazed pasture.

Avermectins are widely used veterinary medicines. They bind strongly to faeces in their non-metabolized form and their half-life in faeces depends on field conditions. There are conflicting data regarding the behaviour of avermectins in the environment.

Introduction of the HPLC method for the determination of quinolone residues in various muscle tissues.

For use in veterinary sanitary control of foodstuffs and raw materials of animal origin in Slovenia, we developed a routine and confirmation analytical method for determining the residues of enrofloxacin, ciprofloxacin and flumequine in the muscle tissue of cattle, pigs and poultry. For the muscle tissue of freshwater fish, the determination of the flumequine residues was introduced. The results obtained through simultaneous determination of the residues of enrofloxacin, ciprofloxacin and flumequine showed that the values for the examined antibiotics were up to 600 times lower than the prescribed maximum residue levels (MRL).