Search

A quantitative weight of evidence (QWoE) methodology was developed to assess confidence in postulated mode(s) of action for adverse effects in animal toxicity studies. The QWoE is appropriate for assessing adverse effects as relevant endpoints for classification and labeling purposes. The methodology involves definition of mode of actions and scoring supporting data for all key steps using predefined criteria for quality and relevance/strength of effects. Scores for all key steps are summarized, and the summary score is compared to the maximal achievable score for the mode of action. The ratio of the summary score to the maximal achievable scores gives an indication of confidence in a specific mode of action in animals. The mode of action in animals with highest confidence is then taken forward to assess appropriateness to humans. If one of the key steps cannot occur in humans, the mode of action is not relevant to humans. The methodology developed is applied to four case studies. [ABSTRACT FROM AUTHOR]

An anonymous, online questionnaire was sent to active diplomates of the American Board of Veterinary Toxicology (DABVTs; n = 95) to determine the attitudes of veterinary toxicologists toward their ABVT certification and the adequacy of the training programs in this discipline. We gathered information related to demographics, educational and work history, and other specialty board membership. Ten questions sought the respondent's opinion related to the economic value of the specialty, whether workforce shortages for DABVT exist, and whether DABVTs should complete a residency or graduate program. Fifty-one (54%) DABVTs responded. Their mean age was 58 and most (88%) held a graduate degree. When respondents were asked to rate their level of agreement (strongly disagree = 1; strongly agree = 5), most (73%) agreed or strongly agreed (median = 4) that there was a shortage of DABVTs. Fourteen (27%) participants strongly disagreed that the ABVT certification was required for their position, while 15 (29%) strongly agreed with this statement (median = 3). Most respondents agreed that the ABVT certification has been critical to their career (median = 4), in addition to a financial benefit to being a DABVT (median = 4). Most (67%) participants strongly or somewhat disagreed that current training programs are adequate to meet the shortage of DABVT (median = 2). Our findings indicate there is concern about the number of DABVTs and the adequacy of training programs to meet this perceived need. These findings improve our understanding of current attitudes of DABVTs toward their specialty. [ABSTRACT FROM AUTHOR]

The epidemiological, clinical and pathological aspects of a spontaneous outbreak of Palicourea aeneofusca poisoning in goats are reported. The main clinical signs were motor incoordination, generalized muscle tremors, broad-based posture, tachypnea, tachycardia, vocalization and respiratory distress. Two goats died 5 and 20 min after the observation of the first clinical signs. Another that was found recumbent died 80 h later. One goat with mild clinical signs recovered. Congestion and hemorrhages were observed macroscopically and histologically in most organs. Pulmonary edema was also observed. The main microscopic findings consisted of cytoplasmic vacuolization and necrosis of the renal tubular epithelium. The average concentration of monofluoroacetate obtained in sixteen samples of P. aeneofusca was 0.29 ± 0.17%. It is concluded that P. aeneofusca is toxic to goats under natural conditions. [ABSTRACT FROM AUTHOR]

The main objectives of this study were to determine the 1,2-dehydropyrrolizidine alkaloid (DHPA) content in Senecio grisebachii Baker (Compositae), to experimentally demonstrate its toxicity in calves and to describe the main clinical and pathological findings of this toxicity. S. grisebachii plants were collected in Paysandú, Uruguay. The concentration and identification of DHPA and associated N -oxides were determined using liquid chromatography-mass spectrometry. Three calves weighing 85–89 kg received doses of 15, 24 or 45 g of dry S. grisebachii per kg of body weight for 6, 10 or 20 days of treatment, respectively. Two animals received no treatment and served as controls. The animals were clinically evaluated, and blood samples were taken to study the serum levels of gamma glutamyltransferase (GGT), aspartate aminotransferase (AST) and alkaline phosphatase (FAS). After death, necropsy was performed and organ samples were taken for histopathological examination. The concentration of DHPA in S. grisebachii was found to be 0.29% (dry weight basis) as free base and 0.08% as N -oxide for a total DHPA concentration of 0.37%. Individual alkaloids identified included seneciophylline, senecionine and retrorsine. The disease was clinically characterized by depression, anorexia, emaciation, colic, dehydration and death in the three animals. Serum concentrations of GGT, AST and FAS were higher than normal beginning on day 7 after start of treatments. Necropsy findings included generalized edema, hemorrhage, ascites and a grayish liver with increased consistency. The main histological lesions were hepatic necrosis, fibrosis, hepatomegalocytosis and bile duct proliferation. The control calves showed no clinical signs of disease. [ABSTRACT FROM AUTHOR]

Poisoning of cattle by larkspur plants ( Delphinium spp.) is a concern for cattle ranchers in western North America. Previous research studies have evaluated the toxicokinetic profile of multiple larkspur toxins in several livestock species. However, those studies were all performed by orally dosing plant material. Consequently some toxicokinetic parameters could not be definitively determined. In this study, we compared the serum toxicokinetic profile of the larkspur alkaloids methyllycaconitine (MLA) and deltaline in goats dosed both IV and via oral gavage. The results from this study indicate that the toxic alkaloids in larkspurs undergo flip-flop kinetics, meaning the rate of absorption of the alkaloids is slower than the rate of elimination. The implications of flip-flop kinetics in treating animals poisoned by larkspur is discussed. [ABSTRACT FROM AUTHOR]

The ability to takeoff quickly and accelerate away from predators is crucial to bird survival. Crude oil can disrupt the fine structure and function of feathers, and here we tested for the first time how small amounts of oil on the trailing edges of the wings and tail of Western sandpipers ( Calidris mauri ) affected takeoff flight performance. In oiled birds, the distance travelled during the first 0.4 s after takeoff was reduced by 29%, and takeoff angle was decreased by 10° compared to unoiled birds. Three-axis accelerometry indicated that oiled sandpipers produced less mechanical power output per wingbeat during the initial phase of flight. Slower and lower takeoff would make oiled birds more likely to be targeted and captured by predators, reducing survival and facilitating the exposure of predators to oil. Whereas the direct mortality of heavily-oiled birds is often obvious and can be quantified, our results show that there are significant sub-lethal effects of small amounts crude oil on feathers, which must be considered in natural resource injury assessments for birds. [ABSTRACT FROM AUTHOR]

Introduction: Lead toxicosis occurs in veterinary patients, with few reports involving rabbits, and no previous reports using oral calcium disodium EDTA. Case report: A 7-year-old male castrated Lionhead rabbit presented to the Cornell University Hospital for Animals (CUHA) for evaluation after a 2-day history of lethargy and a 2-week history of hyporexia. The patient had been observed pulling paint from the walls of the home, a house built circa 1900, in the months prior to presentation. The patient was moderately anemic with a hematocrit of 21% with red blood cell morphological changes consistent with lead toxicosis, including basophilic stippling, nucleated red blood cells, and polychromasia. Radiographic images of the abdomen revealed excessive accumulation of gas in the gastrointestinal tract in a pattern consistent with gastric stasis and numerous small mineral to metallic opacities in the cecum. The blood lead concentration was 792 μg/dL, confirming the diagnosis of lead toxicosis with secondary gastrointestinal stasis. The rabbit was hospitalized for treatment with oral and subcutaneous calcium disodium EDTA for 4 days and then discharged home to the care of the owners. Discussion: Severe lead toxicosis in a rabbit can be treated successfully with oral and subcutaneous calcium disodium EDTA and aggressive supportive treatment. [ABSTRACT FROM AUTHOR]

A subadult male bald eagle ( Haliaeetus leucocephalus) was presented for severe depression and weakness. Physical examination findings included depressed mentation, dehydration, sternal recumbency, poor body condition, and bilateral, whole-head, horizontal nystagmus. A heavy-metal panel was performed, and blood lead levels were 6.1 ppm. Treatment for lead poisoning was initiated, including subcutaneous fluids and parenteral calcium-disodium ethylenediaminetetraacetic acid, ceftiofur, and meloxicam. Ophthalmic examination findings included absent menace response, absent dazzle reflex, slow and incomplete direct pupillary light reflex, mild anterior uveitis, incipient cataracts, multifocal retinal tears, and retinal separation in both eyes. Because of poor prognosis for vision and release to the wild, the eagle was euthanatized. No lesions were observed on gross postmortem examination. Histologically, extensive myocardial necrosis and multisystemic arteriolar vasculopathy were identified. The eyes were examined after tissue processing, and the vasculopathy extended into the choriocapillaris and was associated with a secondary, bilateral, exudative, retinal detachment. This is the first report in avian species characterizing the histopathologic ocular lesions of lead poisoning. [ABSTRACT FROM AUTHOR]

Data of toxicological analyses for baits carried out in the Laboratory of Toxicology of the Department of Veterinary Clinics (University of Pisa) over a 10-year period are summarized. The 508 lures have been grouped according to their preparation features. This classification has generated six classes: (1) baits prepared with discarded or out-of-date food; (2) laborious and original/particular baits; (3) baits containing more than one toxic substance; (4) baits containing non-toxic material; (5) baits prepared with non-food material and (6) in vivo baits. The most commonly detected toxic substances in baits were organophosphorus and carbamate pesticides (48%), anticoagulant rodenticides (18%), zinc phosphide (12%), strychnine (9%), metaldehyde (8%) and others (5%). This survey shows that in Italy, the deliberate misuse or abuse of toxic substances intended to kill domestic animals, is very common and still far from being eradicated. Elaboration of a complex strategy, involving authorities as well as veterinarians and citizens, is the first step to defeat this harmful practice.

Veterinary pathologists working in diagnostic laboratories are sometimes presented with cases involving animal poisonings that become the object of criminal or civil litigation. Forensic veterinary toxicology cases can include cases involving animal cruelty (malicious poisoning), regulatory issues (eg, contamination of the food supply), insurance litigation, or poisoning of wildlife. An understanding of the appropriate approach to these types of cases, including proper sample collection, handling, and transport, is essential so that chain of custody rules are followed and proper samples are obtained for toxicological analysis. Consultation with veterinary toxicologists at the diagnostic laboratory that will be processing the samples before, during, and after the forensic necropsy can help to ensure that the analytical tests performed are appropriate for the circumstances and findings surrounding the individual case. [ABSTRACT FROM AUTHOR]

Bromethalin is a central nervous system toxin currently incorporated into several different rodenticides. In 2008, the EPA requested that manufacturers phase out second-generation anticoagulant rodenticides. In response, manufacturers began to increase production of bromethalin-based rodenticides. It is likely that pet exposure to bromethalin will increase in the future. Bromethalin has no known antidote and tends to deposit in fat. Intravenous lipid emulsions (ILEs) are being used with increasing frequency in both human and veterinary medicine to treat numerous acute systemic toxicities. A 4 yr old spayed female Pit bull terrier was presented following witnessed ingestion of bromethalin rodenticide by the owners. Decontamination was unsuccessful and ILE was started. Serum was frozen at 808C before and 1 hr after completion of ILE. In rats, the half-life of desmethylbromethalin, the toxic metabolite, has been reported at 5.6 days and 6 days, and it is likely to be similar in dogs. The only intervention between the pre-lipid serum sample and the post-lipid serum sample was the administration of ILE, and the serum desmethylbromethalin levels were reduced by 75% (from 4 ppb to 1 ppb) during this time. To the authors' knowledge, this is the first report describing treatment of bromethalin ingestion with ILE. [ABSTRACT FROM AUTHOR]

Background Aflatoxins are secondary metabolites of the fungus Aspergillus sp. The presence of aflatoxin in poultry feeds results in direct toxicity and economic losses, and human health hazards after consumption of contaminated liver and meat. Objectives The study was conducted to assess tissue residues of aflatoxin B1 ( AFB1), and alterations in select clinical chemistry variables in serum during chronic aflatoxicosis in broiler chicks fed different dietary levels of AFB1. Materials and Methods Six groups of broiler chickens were fed diets containing between 0 and 800 ppb of AFB1 for 28 days. Groups of birds were terminated on days 0, 5, 13, 15, 20, and 28, and AFB1 levels were determined by HPLC in liver and muscle. Serum activities of ALT and ALP, and total protein and albumin concentrations were determined. Results No AFB1 residues were detected in liver after 50 ppb AFB1, and muscle after 50 and 100 ppb AFB1 feeding. Residues above the permissible threshold (> 2.0 ng/g) were only detected in liver tissues of groups fed 400 ppb and 800 ppb AFB1 in feed. The ALT and ALP activities in treated groups were significantly higher, and total protein and albumin concentrations were significantly lower in all treated groups compared to controls. Conclusions Continuous feeding of AFB1 to broiler chicken at levels of 50 and 100 ppb for 28 days did not reveal measurable AFB1 residues in muscle tissues. Serum values of ALT, ALP, total protein, and albumin may serve as markers for chronic aflatoxicosis in affected poultry. [ABSTRACT FROM AUTHOR]

AstraZeneca ran a bespoke study to generate age-matched clinical pathology and histopathology data from a cohort of Beagle dogs aged between 25 and 37 months to support the use of these older animals in routine preclinical toxicology studies. As the upper age range of Beagle dogs routinely used in toxicology studies does not normally exceed 24 months, there is an absence of appropriate age-matched historical control data. The generation of such data was crucial to understand whether age-related differences in spontaneous findings might confound the interpretation of toxicology study data. While the majority of the histopathology findings in all the older dogs occurred at a similar prevalence as those expected in young adult dogs (<24 months), a number of differences were observed in the thymus (involution), bone marrow (increased adiposity), testes (degenerative changes), and lung (fibrosis, pigment and alveolar hyperplasia) that could be misinterpreted as a test article effect. Minor differences in some clinical pathology values (hemoglobin, alkaline phosphatase, absolute reticulocytes) were of a small magnitude and considered unlikely to affect the interpretation of study data. [ABSTRACT FROM AUTHOR]

OBJECTIVE To identify clinical signs associated with oral exposure to black walnut tree (Juglans nigra) wood, nuts, or nut hulls in dogs and to compare clinical syndromes between dogs that ingested wood and dogs that ingested the walnuts or nut hulls. DESIGN Retrospective case series. ANIMALS 93 dogs. PROCEDURES Records of dogs with oral exposure to black walnut wood, nuts, or nut hulls between November 2001 and December 2012 were retrieved from the Animal Poison Control Center database. Records were reviewed, and data regarding signalment; exposure; time of onset, type, and duration of clinical signs; serum biochemical abnormalities; treatment; and response to treatment were collected. Results were compared statistically between dogs that ingested wood and those that ingested nut components. RESULTS 28 cases involved exposure to wood, and 65 involved exposure to nuts or hulls. Spontaneous vomiting was commonly observed (13/28 [46%] and 31 /65 [48%] dogs that ingested wood and nut components, respectively). Neurologic or musculoskeletal signs were significantly more common in dogs that ingested wood (26/28 [93%]) than in those that ingested nuts or hulls (15/65 [23%]). Relative risk of developing neurologic signs after ingestion of wood was approximately 4 times that after ingestion of nuts or hulls. CONCLUSIONS AND CLINICAL RELEVANCE Ingestion of black walnut wood by dogs resulted in a clinical syndrome in which neurologic or musculoskeletal signs were most frequently reported, whereas ingestion of black walnuts or their hulls was most commonly associated with vomiting. To our knowledge, this is the first report describing 2 different clinical syndromes associated with exposure to black walnut tree components in dogs. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Veterinary Journal / Revue Vétérinaire Canadienne is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alkaloids, nitrogen-containing secondary plant metabolites, are of major interest to veterinary toxicology because of their occurrence in plant species commonly involved in animal poisoning. Based on epidemiological data, the poisoning of cattle and horses by alkaloid-containing plants is a relatively common occurrence in Europe. Poisoning may occur when the plants contaminate hay or silage or when forage alternatives are unavailable. Cattle and horses are particularly at risk of poisoning by Colchicum autumnale (meadow saffron), Conium maculatum (poison hemlock), Datura stramonium (jimson weed), Equisetum palustre (marsh horsetail), Senecio spp. (ragwort and groundsel) and Taxus baccata (European yew). This review of poisonous alkaloid-containing plants describes the distribution of these plants, conditions under which poisoning occurs, active toxic principles involved and subsequent clinical signs observed. [ABSTRACT FROM AUTHOR]

The article presents information on fipronil toxicosis in rabbits. Topics discussed include the topical spot-on product labeled for use in dogs and cats; how fipronil blocks GABA receptors in the central nervous system that results in excessive central nervous system stimulation and death; and several cases taken from ASPCA Animal Poison Control Center's toxicology database from 2003 to 2014.

Summary Venomous animals have toxins associated with delivery mechanisms that can introduce the toxins into another animal [ 1 ]. Although most amphibian species produce or sequester noxious or toxic secretions in the granular glands of the skin to use as antipredator mechanisms [ 2, 3 ], amphibians have been considered poisonous rather than venomous because delivery mechanisms are absent. The skin secretions of two Brazilian hylid frogs ( Corythomantis greeningi [ 4 ] and Aparasphenodon brunoi ) are more toxic than the venoms of deadly venomous Brazilian pitvipers, genus Bothrops [ 5 ]; C. greeningi secretion is 2-fold and A. brunoi secretion is 25-fold as lethal as Bothrops venom. Like the venoms of other animals, the skin secretions of these frogs show proteolytic and fibrinolytic activity and have hyaluronidase, which is nontoxic and nonproteolytic but promotes diffusion of toxins. These frogs have well-developed delivery mechanisms, utilizing bony spines on the skull that pierce the skin in areas with concentrations of skin glands. C. greeningi has greater development of head spines and enlarged skin glands producing a greater volume of secretion, while A. brunoi has more lethal venom. C. greeningi and A. brunoi have highly toxic skin secretions and an associated delivery mechanism; they are therefore venomous. Because even tiny amounts of these secretions introduced into a wound caused by the head spines could be dangerous, these frogs are capable of using their skin toxins as venoms against would-be predators. [ABSTRACT FROM AUTHOR]

Ethephon (C2H6ClO3P) (ETP) is indiscriminately used as a pre and post-harvest ripening agent in a variety of marketed fruits. The mode of action of ripening by ETP is mediated on liberation of the natural plant ripening hormone-ethylene. ETP also belongs to the class of organophosphorus pesticides. Under this background, the present study was undertaken to evaluate the toxic effect of ETPin the haematological picture of albino rat exposed repeatedly to two different doses of ETP viz. 25 mg, 50 mg/kg body wt./day for a period of 90 days through oral administration. The study was carried out on the basis of cytomorphological and numerical alterations of different blood cells. Cytomorphological and numerical level of different haematological indices such as TLC (total leucocyte count), DLC (differential leucocyte count), TEC (total erythrocyte count), Hb (Haemoglobin) content and PCV (packed cell volume) were performed following standard methods. Findings of the present study showed a progressive increase in the TLC with an abnormal count of DLC in chemical treated groups compared to their normal counterparts. However, a gradual depletion of Hb content, PCV and TEC were found in all the treated groups. Cytomorphological changes of disc shaped erythrocytes manifested numerous stomatocytes appearance with central pallor, discocyte asymmetry and various forms of membrane deformities, macroscopic hypochromic ring and teardrop-shaped cells. Appearance of Heinz bodies in the erythrocyte was another marked feature of cellular abnormalities. Various immature WBC like ring type eosinophils and blast formation of granulocytic series, fragmented neutrophil along with membrane irregularity in many white blood cells were also evident in the peripheral blood film. Analysis of the present findings concluded that ETP is a potent agent that can cause alterations in the blood picture at cytomorphological and numerical level. Therefore, it establishes the haematotoxic nature of the chemical. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 4-year-old spayed domestic shorthaired cat which was presented to an emergency veterinary clinic for evaluation of lethargy and flatulence of four hour's duration. It says that the cat had ingested onions cooked in butter about 10 to 12 hours before the lethargy and flatulence started. The case management of the cat and various laboratory procedures are detailed, along with information on onion toxicity.

The article presents epidemiologic observations of strychnine poisoning in dogs in western Canada from 1998 to 2013 for the purpose of evaluating suspected cases of poisoning. It mentions that the analysis showed no statistical differences in terms of age or gender and revealed that male dogs were more commonly affected strychnine poisoning. It concludes that strychnine poisoning is common toxicosis in the dogs of western Canada.

Background High levels of lead, up to 3.3 mg/kg fresh weight, were detected in pig liver in Western Australia at the beginning of 2008. This followed the detection of lead at above the maximum level ( ML) in a pig liver through the National Residue Survey ( NRS). The contamination source was traced back to a zinc oxide feed additive used early post-weaning that contained in excess of 8% lead. Methods and Results Confirmation of the source of lead contamination was obtained by comparing lead isotope ratios for the zinc oxide and the pig livers. The investigation demonstrated the importance of verifying the safety of feed and feed ingredients prior to incorporation in feed. Retrospective analysis of NRS data indicated that the level of lead needed to trigger an investigation for intensively housed pigs should be considerably lower than the ML. As a result, investigations in Australia will now be conducted when levels of lead in pig liver exceed 0.1 mg/kg fresh weight. Conclusions Despite the potential for small amounts of non-compliant kidney and liver to enter the human food chain, there was no significant increase in the risk to consumers. [ABSTRACT FROM AUTHOR]

Veterinary pathologists working as toxicologic pathologists in academic settings fill many vital roles, such as diagnosticians, educators, and/or researchers. These individuals have spent years investigating pathology problems that mainly or exclusively focus on the reactions of cells, organs, or systems to toxic materials. Thus, academic toxicologic pathologists are uniquely suited both to help trainees understand toxicity as a cause of pathology responses and also to provide expert consultation on toxicologic pathology. Most toxicologic pathologists in academia are employed at colleges of medicine or veterinary medicine, even though specific toxicologic pathology faculty appointments are uncommon in Europe and North America. Academic toxicologic pathologists typically receive lower financial compensation than do toxicologic pathologists in industry, but academic positions generally provide alternative rewards, such as higher workplace autonomy and scheduling flexibility, professional enrichment through student interactions, and enhanced opportunities for collaborative research and advanced diagnostic investigations. Regular participation by academic toxicologic pathologists in professional training opportunities (eg, as pathology and toxicology instructors in medical and veterinary medical courses, graduate programs, and residencies) offers an important means of engendering interest and inspiring veterinarians to select toxicologic pathology and toxicology as their own areas of future expertise. [ABSTRACT FROM PUBLISHER]

The article offers information on the contributions of the American Board of Veterinary Toxicology (ABVT) which is celebrating its 50th anniversary in 2017. Topics covered include a brief retrospective into the development of veterinary toxicology, the current contributions and status of the field of veterinary toxicology, and the contributions of veterinarians to toxicology and environmental health research.

Microcystins are acute hepatotoxins of increasing global concern in drinking and recreational waters and are a major health risk to humans and animals. Produced by cyanobacteria, microcystins inhibit serine/threonine protein phosphatase 1 (PP1). A cost-effective PP1 assay using p-nitrophenyl phosphate was developed to quickly assess water and rumen content samples. Significant inhibition was determined via a linear model, which compared increasing volumes of sample to the log-transformed ratio of the exposed rate over the control rate of PP1 activity. To test the usefulness of this model in diagnostic case investigations, samples from two veterinary cases were tested. In August 2013 fifteen cattle died around two ponds in Kentucky. While one pond and three tested rumen contents had significant PP1 inhibition and detectable levels of microcystin-LR, the other pond did not. In August 2013, a dog became fatally ill after swimming in Clear Lake, California. Lake water samples collected one and four weeks after the dog presented with clinical signs inhibited PP1 activity. Subsequent analysis using liquid chromatography-mass spectrometry (LC-MS/MS) detected microcystin congeners -LR, -LA, -RR and -LF but not -YR. These diagnostic investigations illustrate the advantages of using functional assays in combination with LC-MS/MS.

Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. A potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. For two consecutive years we quantified the level lead exposure in individuals of a sentinel scavenger species, the common raven (Corvus corax), captured during the moose (Alces alces) hunting season in eastern Quebec, Canada. The source of the lead contamination was also determined using stable isotope analyses. Finally, we identified the different scavenger species that could potentially be exposed to lead by installing automatic cameras targeting moose gut piles. Blood lead concentration in ravens increased over time, indicating lead accumulation over the moose-hunting season. Using a contamination threshold of 100 µg.L−1, more than 50% of individuals were lead-contaminated during the moose hunting period. Lead concentration was twice as high in one year compared to the other, matching the number of rifle-shot moose in the area. Non-contaminated birds exhibited no ammunition isotope signatures. The isotope signature of the lead detected in contaminated ravens tended towards the signature from lead ammunition. We also found that black bears (Ursus americanus), golden eagles and bald eagles (Aquila chrysaetos and Haliaeetus leucocephalus, two species of conservation concern) scavenged heavily on moose viscera left by hunters. Our unequivocal results agree with other studies and further motivate the use of non-toxic ammunition for big game hunting. [ABSTRACT FROM AUTHOR]

The article presents a case study of dog with toxicosis. It states that a year-old Australian shepherd after chewing on two AA alkaline batteries was presented to a veterinary clinic for evaluation. It states the dog which was bright and alert during physical examination, showed signs of oral irritation. However, after 18 hours, it showed, signs of moderate ulceration of the buccal mucosa and tongue, for which it was hospitalized, and treated with tramadol and amoxicillin-clavulanic acid.

In this study, a sensitive dual-label time-resolved reverse competitive chemiluminescent immunoassay was developed for simultaneous detection of chloramphenicol (CAP) and clenbuterol (CLE) in milk. The strategy was performed based on the distinction of the kinetic characteristics of horseradish peroxidase (HRP) and alkaline phosphatase (ALP) in chemiluminesecence (CL) systems and different orders of magnitude in HRP CL value for CAP and ALP CL value for CLE in the chemiluminescent immunoassay. Capture antibodies were covalently bound to the amine group functionalized chemiluminescent microtiter plate (MTP) for efficient binding of detection antibodies for the enzymes labeled CAP (HRP-CAP) and CLE (ALP-CLE). The CL signals were recorded at different time points by the automatic luminometers with significant distinction in the dynamic curves. When we considered the ALP CL value (about 105) of CLE as background for HRP CL signal value (about 107) of CAP, there was no interaction from ALP CL background of CLE and the differentiation of CAP and CLE can be easily achieved. The 50% inhibition concentration (IC50) values of CAP and CLE in milk samples were 0.00501 µg L−1 and 0.0128 µg L−1, with the ranges from 0.0003 µg L−1 to 0.0912 µg L−1 and from 0.00385 µg L−1 to 0.125 µg L−1, respectively. The developed method is more sensitive and of less duration than the commercial ELISA kits, suitable for simultaneous screening of CAP and CLE. [ABSTRACT FROM AUTHOR]

The effects of intravenous (IV) lidocaine, dexmedetomidine and their combination delivered as a bolus followed by a constant rate infusion (CRI) on the minimum alveolar concentration of isoflurane (MACISO) in dogs were evaluated. Seven healthy adult dogs were included. Anaesthesia was induced with propofol and maintained with isoflurane. For each dog, baseline MAC (MACISO/BASAL) was determined after a 90-minute equilibration period. Thereafter, each dog received one of the following treatments (loading dose, CRI): lidocaine 2 mg kg−1, 100 µg kg−1 minute−1; dexmedetomidine 2 µg kg−1, 2 µg kg−1 hour−1; or their combination. MAC was then determined again after 45- minutes of treatment by CRI. At the doses administered, lidocaine, dexmedetomidine and their combination significantly reduced MACISO by 27.3% (range: 12.5–39.2%), 43.4% (33.3–53.3%) and 60.9% (46.1–78.1%), respectively, when compared to MACISO/BASAL. The combination resulted in a greater MACISO reduction than the two drugs alone. Their use, at the doses studied, provides a clinically important reduction in the concentration of ISO during anaesthesia in dogs. [ABSTRACT FROM AUTHOR]

Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001). DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001) and decreased duodenal villus height (P = 0.014) indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023). Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens. [ABSTRACT FROM AUTHOR]

Cadmium ions (Cd2+) have been reported to accumulate in bovine tissues, although Cd2+ cytotoxicity has not been investigated thoroughly in this species. Zinc ions (Zn2+) have been shown to antagonize the toxic effects of heavy metals such as Cd2+ in some systems. The present study investigated Cd2+ cytotoxicity in Madin-Darby bovine kidney (MDBK) epithelial cells, and explored whether this was modified by Zn2+. Exposure to Cd2+ led to a dose- and time-dependent increase in apoptotic cell death, with increased intracellular levels of reactive oxygen species and mitochondrial damage. Zn2+ supplementation alleviated Cd2+-induced cytotoxicity and this protective effect was more obvious when cells were exposed to a lower concentration of Cd2+ (10 μM), as compared to 50 μM Cd2+. This indicated that high levels of Cd2+ accumulation might induce irreversible damage in bovine kidney cells. Metallothioneins (MTs) are metal-binding proteins that play an essential role in heavy metal ion detoxification. We found that co-exposure to Zn2+ and Cd2+ synergistically enhanced RNA and protein expression of MT-1, MT-2, and the metal-regulatory transcription factor 1 in MDBK cells. Notably, addition of Zn2+ reduced the amounts of cytosolic Cd2+ detected following MDBK exposure to 10 μM Cd2+. These findings revealed a protective role of Zn2+ in counteracting Cd2+ uptake and toxicity in MDBK cells, indicating that this approach may provide a means to protect livestock from excessive Cd2+ accumulation. [ABSTRACT FROM AUTHOR]

Background: CD37 is an internalizing B-cell antigen expressed on Non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia cells (CLL). The anti-CD37 monoclonal antibody HH1 was conjugated to the bifunctional chelator p-SCN-Bn-DOTA and labelled with the beta-particle emitting radionuclide 177Lu creating the radio-immunoconjugate (RIC) 177Lu-DOTA-HH1 (177Lu-HH1, trade name Betalutin). The present toxicity study was performed prior to initiation of clinical studieswith 177Lu-HH1. Methodology/Principal Findings: Nude mice with or without tumor xenografts were treated with 50 to 1000 MBq/kg 177Lu- HH1 and followed for clinical signs of toxicity up to ten months. Acute, life threatening bone marrow toxicity was observed in animals receiving 800 and 1000 MBq/kg 177Lu-HH1. Significant changes in serum concentrations of liver enzymes were evident for treatment with 1000 MBq/kg 177Lu-HH1. Lymphoid depletion, liver necrosis and atrophy, and interstitial cell hyperplasia of the ovaries were also observed for mice in this dose group. Conclusions/Significance: 177Lu-DOTA-HH1 was well tolerated at dosages about 10 times above those considered relevant for radioimmunotherapy in patients with B-cell derived malignancies.The toxicity profile was as expected for RICs. Our experimental results have paved the way for clinical evaluation of 177Lu-HH1 in NHL patients. [ABSTRACT FROM AUTHOR]

As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions. From July 2011 to May 2012, 330 colonies were monitored. Honeybees, wax, beebread and honey samples were collected. Morbidity and mortality information provided by beekeepers, colony clinical visits and availability of analytical matrix were used to form 2 groups: healthy colonies and colonies with disorders (n = 29, n = 25, respectively). Disorders included: (1) dead colonies or colonies in which part of the colony appeared dead, or had disappeared; (2) weak colonies; (3) queen loss; (4) problems linked to brood and not related to any known disease. Five common viruses and 99 pesticides (41 fungicides, 39 insecticides and synergist, 14 herbicides, 5 acaricides and metabolites) were quantified in the samples.The main symptoms observed in the group with disorders are linked to brood and queens. The viruses most frequently found are Black Queen Cell Virus, Sac Brood Virus, Deformed Wing Virus. No significant difference in virus load was observed between the two groups. Three acaricides, 5 insecticides and 13 fungicides were detected in the analysed samples. A significant correlation was found between the presence of fungicide residues and honeybee colony disorders. A significant positive link could also be established between the observation of disorder and the abundance of crop surface around the beehive. According to our results, the role of fungicides as a potential stressor for honeybee colonies should be further studied, either by their direct and/or indirect impacts on bees and bee colonies. [ABSTRACT FROM AUTHOR]

Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect the membrane insertion domain behaved as dominant-negative inhibitors of toxin activity in MDCK cells. We produced similar mutants, together with a well-known non-toxic mutant (Etx-H106P), as green fluorescent protein (GFP) fusion proteins to perform in vivo studies in an acutely intoxicated mouse model. The mutant (GFP-Etx-I51C/A114C) had a lethal effect with generalized edema, and accumulated in the brain parenchyma due to its ability to cross the blood-brain barrier (BBB). In the renal system, this mutant had a cytotoxic effect on distal tubule epithelial cells. The other mutants studied (GFP-Etx-V56C/F118C and GFP-Etx-H106P) did not have a lethal effect or cross the BBB, and failed to induce a cytotoxic effect on renal epithelial cells. These data suggest a direct correlation between the lethal effect of the toxin, with its cytotoxic effect on the kidney distal tubule cells, and the ability to cross the BBB. [ABSTRACT FROM AUTHOR]

Background: Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. Methods: We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. Results: All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. Conclusion: The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion, deflection angle, cavity shape, and reproducibility, showing that similar terminal ballistic behavior can be achieved. Furthermore, the volumetric image processing allowed superior analysis compared to methods that involve cutting of the soap blocks. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants are a concern for species occupying high trophic levels since they can cause immunosuppression and impair reproduction. Mass mortalities due to canine distemper virus (CDV) occurred in Caspian seals (Pusa caspica), in spring of 1997, 2000 and 2001, but the potential role of organochlorine exposure in these epizootics remains undetermined. Here we integrate Caspian seal mortality data spanning 1971–2008, with data on age, body condition, pathology and blubber organochlorine concentration for carcases stranded between 1997 and 2002. We test the hypothesis that summed PCB and DDT concentrations contributed to CDV associated mortality during epizootics. We show that age is the primary factor explaining variation in blubber organochlorine concentrations, and that organochlorine burden, age, sex, and body condition do not account for CDV infection status (positive/negative) of animals dying in epizootics. Most animals (57%, n = 67) had PCB concentrations below proposed thresholds for toxic effects in marine mammals (17 µg/g lipid weight), and only 3 of 67 animals had predicted TEQ values exceeding levels seen to be associated with immune suppression in harbour seals (200 pg/g lipid weight). Mean organonchlorine levels were higher in CDV-negative animals indicating that organochlorines did not contribute significantly to CDV mortality in epizootics. Mortality monitoring in Azerbaijan 1971–2008 revealed bi-annual stranding peaks in late spring, following the annual moult and during autumn migrations northwards. Mortality peaks comparable to epizootic years were also recorded in the 1970s–1980s, consistent with previous undocumented CDV outbreaks. Gompertz growth curves show that Caspian seals achieve an asymptotic standard body length of 126–129 cm (n = 111). Males may continue to grow slowly throughout life. Mortality during epizootics may exceed the potential biological removal level (PBR) for the population, but the low frequency of epizootics suggest they are of secondary importance compared to anthropogenic sources of mortality such as fishing by-catch. [ABSTRACT FROM AUTHOR]