Diagnostic Challenges and Guidelines Pertaining to Suspected Ruminant Intoxications.

This article addresses diagnostic challenges involving toxicology cases that are multifactorial in nature, often involving sublethal exposures to multiple toxicants and/or other etiologies that are not toxic. Gold standard diagnostic approaches were developed under the assumption that cases were undoubtedly intoxications, and they still are applicable to those cases. A more integrated diagnostic approach, focusing on the initial problem list, is consistent with how veterinarians diagnose most cases. Livestock ownership attitudes continue to evolve. Ongoing threats to the financial well-being of animal agriculture ultimately will have an impact on the ability of producers to maintain health and performance of livestock.

Commercial and Industrial Chemical Hazards for Ruminants: An Update.

Livestock can be exposed to a wide variety of commercial or industrial chemicals that have variable toxicity. Adverse effects can be due to acute or chronic illnesses and deaths or due to contamination of meat or milk intended for human consumption. A diagnosis can be challenging in the absence of a known exposure. It is critical that a complete evaluation be conducted and appropriate samples be collected for possible analysis. Appropriate experts and regulatory agencies should be consulted as soon as possible to avoid potential contaminated animal products reaching consumers.

Veterinary pharmacovigilance in sub-Sahara Africa context: a pilot study of adverse reactions to veterinary medicine in Cameroon.

BACKGROUND: Sub-Saharan African market is highly affected by counterfeit veterinary drugs. Though these counterfeit and non-compliance of drugs can induce adverse effects during their utilization, there is no monitoring system of veterinary medicines. The present pilot study was carried out in Cameroon to identify and describe suspected cases of adverse reactions to veterinary drugs in animals and / or humans as well as inefficacy of veterinary drugs. The methodology involved a descriptive cross-sectional survey of 67 actors in the veterinary medicine sector in Cameroon. RESULTS: A total of 74/120 (62%) cases of suspected adverse effects and or lack of efficacy of veterinary drugs in animals and 46 (38%) cases of adverse reactions in humans were identified. Antiparasitics were the most incriminated therapeutic class in animals (61%) and human (56%). Adverse reactions were reported in dogs (44%) and poultry (24%) while drug inefficacy was most observed in poultry (47%). According to animal health professionals, levamisole (24%) and ivermectin (16%) were identified to be responsible for the adverse effects and that the highest level of inefficacy was most frequently reported for oxytetracycline (29%). The main adverse reactions were systemic (22%), gastrointestinal (20%) and neurological (13%) disorders. CONCLUSION: The results of this study showed that misuse and circulation of poor quality as well as lack of efficacy of veterinary drugs is very common in Cameroon. Adverse reactions were observed in animals and humans. Therefore, the establishment of a national veterinary pharmacovigilance system based on solid legal bases is essential for a continuous assessment of the risks-benefits effects of veterinary drugs marketed in Cameroon.

Heap leach cyanide irrigation and risk to wildlife: Ramifications for the international cyanide management code.

Exposed cyanide-bearing solutions associated with gold and silver recovery processes in the mining industry pose a risk to wildlife that interact with these solutions. This has been documented with cyanide-bearing tailings storage facilities, however risks associated with heap leach facilities are poorly documented, monitored and audited. Gold and silver leaching heap leach facilities use cyanide, pH-stabilised, at concentrations deemed toxic to wildlife. Their design and management are known to result in exposed cyanide-bearing solutions that are accessible to and present a risk to wildlife. Monitoring of the presence of exposed solutions, wildlife interaction, interpretation of risks and associated wildlife deaths are poorly documented. This paper provides a list of critical monitoring criteria and attempts to predict wildlife guilds most at risk. Understanding the significance of risks to wildlife from exposed cyanide solutions is complex, involving seasonality, relative position of ponding, temporal nature of ponding, solution palatability, environmental conditions, in situ wildlife species inventory and provision of alternative drinking sources for wildlife. Although a number of heap leach operations are certified as complaint with the International Cyanide Management Code (Cyanide Code), these criteria are not considered by auditors nor has systematic monitoring regime data been published. Without systematic monitoring and further knowledge, wildlife deaths on heap leach facilities are likely to remain largely unrecorded. This has ramifications for those operations certified as compliance with the Cyanide Code.

Ecological and human health risks associated with abandoned gold mine tailings contaminated soil.

Gold mining is a major source of metal and metalloid emissions into the environment. Studies were carried out in Krugersdorp, South Africa, to evaluate the ecological and human health risks associated with exposure to metals and metalloids in mine tailings contaminated soils. Concentrations of arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) in soil samples from the area varied with the highest contamination factors (expressed as ratio of metal or metalloid concentration in the tailings contaminated soil to that of the control site) observed for As (3.5x102), Co (2.8x102) and Ni (1.1x102). Potential ecological risk index values for metals and metalloids determined from soil metal and metalloid concentrations and their respective risk factors were correspondingly highest for As (3.5x103) and Co (1.4x103), whereas Mn (0.6) presented the lowest ecological risk. Human health risk was assessed using Hazard Quotient (HQ), Chronic Hazard Index (CHI) and carcinogenic risk levels, where values of HQ > 1, CHI > 1 and carcinogenic risk values > 1×10-4 represent elevated risks. Values for HQ indicated high exposure-related risk for As (53.7), Cr (14.8), Ni (2.2), Zn (2.64) and Mn (1.67). Children were more at risk from heavy metal and metalloid exposure than adults. Cancer-related risks associated with metal and metalloid exposure among children were also higher than in adults with cancer risk values of 3×10-2 and 4×10-2 for As and Ni respectively among children, and 5×10-3 and 4×10-3 for As and Ni respectively among adults. There is significant potential ecological and human health risk associated with metal and metalloid exposure from contaminated soils around gold mine tailings dumps. This could be a potential contributing factor to a setback in the health of residents in informal settlements dominating this mining area as the immune systems of some of these residents are already compromised by high HIV prevalence.

The role of a PSP-producing Alexandrium bloom in an unprecedented diamondback terrapin (Malaclemys terrapin) mortality event in Flanders Bay, New York, USA.

Diamondback terrapins (Malaclemys terrapin) are a threatened or endangered species in much of their range along the U.S. Atlantic and Gulf coasts. Over an approximately three-week period from late April to mid-May 2015, hundreds of adult diamondback terrapins were found dead on the shores of Flanders Bay, Long Island, New York, USA. Concurrent with the mortality event, elevated densities of the paralytic shellfish toxin (PST)-producing dinoflagellate, Alexandrium fundyense (>104 cells L-1) and high levels of PST in bivalves (maximal levels = 540 µg STX eq. 100 g-1 shellfish tissue) were observed in the Flanders Bay region, resulting in shellfish bed closures in regional tributaries. Gross and histologic postmortem examinations of terrapins revealed no physical trauma to individuals or a common, underlying disease process to explain the deaths. PST compounds (0.2-12.5 µg STX eq. 100 g-1) were present in various M. terrapin tissues collected over the duration of the mortality event. High-throughput sequencing revealed that the ribbed mussel (Geukensia demissa, a PST vector) was present in the gastrointestinal tracks of all terrapin samples tested. While the potential of PST to cause mortality in chelonians has not been well-characterized, in the absence of other significant findings from necropsies and pathological analyses, we provide evidence that PST in shellfish was likely high enough to cause or contribute to the mortality in these small (<2.0 kg) animals.

Natural incidence of zearalenone in Croatian pig feed, urine and meat in 2014.

The aim of this study was to determine the levels of zearalenone (ZEN) in different feed materials and feedstuffs for pigs, as well as in pig urine and pig meat following contaminated feed consumption. In total, 253 feed material and feedstuff samples were collected from Croatian pig farms. The results revealed the presence of ZEN in significant concentrations, the maximal being found in maize (5522 µg/kg), wheat (3366 µg/kg) and pig fattening feed (1949 µg/kg). In farms in which high feed contamination and pig hyperestrogenism were observed, samples of pig urine (n=30) and meat (n=30) were retrieved as well. The mean ZEN concentrations in pig urine and pig meat were 206±20.6 µg/L and 0.62±0.14 µg/kg, respectively. Despite high contamination of feedstuffs responsible for farmed pigs' intoxication, ZEN levels determined in pig meat were shown to be of little significance for human safety.

Low doses of ivermectin cause sensory and locomotor disorders in dung beetles.

Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin's effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.

Domoic acid epileptic disease.

Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

Epidemiology of intoxication of domestic animals by plants in Europe.

This review focuses on some of the most important poisonous plants in Europe and provides an overview of the poisoning episodes that have occurred in European countries. Poisoning of livestock and companion animals by plants is a relatively common occurrence. In Europe livestock and horses are commonly poisoned by Datura stramonium (Jimson weed), Senecio spp. (ragworts and groundsels), Quercus spp. (oak), Taxus baccata (European yew), Nerium oleander (oleander), Pteridium aquilinum (bracken fern), Robinia pseudoacacia (black locust) and Rhododendron spp. (rhododendrons and azaleas). Poisoning may occur when the fresh plant is ingested in pasture or when it contaminates hay or silage. In pets, the greatest majority of plant poisonings are the result of ingestion of house or garden plants, such as Cycas revoluta (Sago palm), Ricinus communis (castor bean), Allium spp., Euphorbia pulcherrima (poinsettia), Lilium spp., Convallaria majalis (Lily of the valley), Pyracantha spp. (firethorn), Rhododendron spp. (rhododendrons and azaleas), Melia azedarach (Chinaberry tree), Taxus baccata (European yew) and Nerium oleander (oleander).

[Important toxic and undesirable effects of medicaments in animals from the pharmacists viewpoint]. / Významné toxické a nezádoucí úcinky léku u zvírat z pohledu lékárníka.

Both veterinary and human drugs belong to the most common sources of poisoning in companion animals. The most problematic are "over the counter" drugs, mainly those from the group of analgesics, which are often given to animals by their owners who are not informed about their toxicity to animals, and those from the group of antiparasitics, which are often administered in an improper dose and to improper animal species. Pharmacists should play an important role in the education of their clients and animal owners in this field. To be able to give qualified advice and thus decrease the possibility of animal poisoning by drugs, they need to obtain sufficient and up-to-date information in this issue. The aim of this overview is to supply pharmacists with the most important knowledge from the area of drug toxicology in small animals.

Invited review: Efficacy, metabolism, and toxic responses to chlorate salts in food and laboratory animals.

For over 100 yr, scientists have explored uses of sodium chlorate in agricultural applications. Sodium chlorate is a strong oxidizer, and thus can be very hazardous when not handled accordingly. Nevertheless, late 19th century agriculturists and scientists attempted to exploit the chemical properties of sodium chlorate as an herbicide and food preservative. It is the herbicidal utility that led to subsequent use of sodium chlorate in the agricultural industry since then. However, in 2000, USDA-ARS scientists proposed a new and targeted use of sodium chlorate against enterobacteria in food animal production. Specifically, when orally dosed in to cattle (Bos taurus), swine (Sus scrofa), broilers (Gallus gallus), turkeys (Meleagris gallopavo), and sheep (Ovis aries), chlorate reduced the fecal shedding of common enteropathogens of the Enterobacteriaceae family. Subsequent to this discovery, the efficacy of chlorate salts has been demonstrated in numerous production classes within species. Doses of sodium chlorate as low as 30 mg/kg BW, but typically 50 to 150 mg/kg BW, have been used to demonstrate efficacy against pathogens. Single or short-duration (<3 d) exposures to oral chlorate at concentrations < 150 mg/kg BW have not produced acute toxicity or clinical signs (labored breathing, methemoglobinemia) in food animals. In all species studied to date, the major biotransformation product of chlorate is chloride ion; chlorite is not present in tissues or excreta of chlorate dosed animals. Chlorate is rapidly eliminated in ruminants and nonruminants, primarily in urine; likewise, residual chlorate in tissues depletes rapidly. Application of any new chemical entity to food animal production carries with it a responsibility to understand adverse reactions that intended and nonintended exposures may have in target and (or) nontarget animals and an understanding of the pathways of elimination that occur after exposure. Therefore, the purpose of this review is to summarize the published data regarding the efficacy, metabolism, and toxicology of chlorate salts in target (livestock) and nontarget species.

Impacts of gas drilling on human and animal health.

Environmental concerns surrounding drilling for gas are intense due to expansion of shale gas drilling operations. Controversy surrounding the impact of drilling on air and water quality has pitted industry and lease-holders against individuals and groups concerned with environmental protection and public health. Because animals often are exposed continually to air, soil, and groundwater and have more frequent reproductive cycles, animals can be used as sentinels to monitor impacts to human health. This study involved interviews with animal owners who live near gas drilling operations. The findings illustrate which aspects of the drilling process may lead to health problems and suggest modifications that would lessen but not eliminate impacts. Complete evidence regarding health impacts of gas drilling cannot be obtained due to incomplete testing and disclosure of chemicals, and nondisclosure agreements. Without rigorous scientific studies, the gas drilling boom sweeping the world will remain an uncontrolled health experiment on an enormous scale.

Diagnostic guidelines for ruminant toxicoses.

Management of poisoning is best accomplished when an accurate diagnosis is made and enhanced by attention to five major diagnostic criteria: history, clinical signs, clinical laboratory evaluation, lesions, and chemical analysis. Used properly, all of these factors allow for a better understanding of clinical poisoning. Although not all of these are possible for individual incidents, a systematic approach to support these criteria will bring a more useful assessment of risk and an accurate diagnosis. This article covers key principles of diagnostic toxicology and provides specific suggestions for clinical, laboratory, postmortem, and chemical testing to best suggest and confirm a toxicologic diagnosis.

Ionophore toxicity and tolerance.

The rapid growth of the biofuels industry in the Midwest in the past 10 years has created an increased supply of corn coproduct feed for animals. This article discusses the tolerance and toxicology of biofuels coproducts in ruminants, including polioencephalomalacia, sulfur toxicosis, sulfur metabolism, mycotoxins, antibiotic residue, and biodiesel by-product toxicosis.

Commercial and industrial chemical hazards for ruminants.

There are many potentially hazardous commercial or industrial products used in or around ruminant environments. Although some products are highly toxic, their proper storage and use minimize their hazard to ruminants. Although most exposures to such materials occur via ingestion, inhalation or dermal exposures also are possible. The diagnosis of intoxication requires both thorough antemortem and postmortem examination of affected animals and thorough investigation of their environment. Fortunately, intoxications from such materials are relatively infrequent. The possibility of residues affecting meat or milk from exposed animals always needs to be considered.

Safety of antibiotic drugs in food animals: comparison of findings from preapproval studies and postapproval experience in the United States with safety information in published literature.

Antibiotics are among the most widely prescribed drugs and are generally considered safe for the target species. However, their use has been associated with various adverse toxic effects in target animals, such as allergic reactions, gastrointestinal signs, cardiovascular effects, hypoglycemia, hepatic/renal toxicity, thrombocytopenia, and anaphylaxis. This article provides a qualitative summary of the adverse events observed in target animals during the evaluation of antibiotics by the Food and Drug Administration during both preapproval and postapproval periods. As there is a marked scarcity of published data on safety of antibiotics in food animals, more research is needed in this area.

Effects of xenobiotics and phytotoxins on reproduction in food animals.

As man-made chemicals (anthropogenic) are increasing in number and amount of use, it is not uncommon for farmers, ranchers, consultants, or veterinarians to suspect a xenobiotic (strange or foreign substance) as the cause of reproductive failures. In this article, the authors discuss toxicants that have been shown to affect reproduction, with emphasis on food-producing animals and fowl. The discussion is brief, and written to provide a resource for clinicians, students, and scientists by focusing on toxicant-induced reproductive dysfunction relevant to the toxicant, source, clinical effects, and livestock species known or suspected to be affected.

Southeastern plants toxic to ruminants.

Selected toxic plants affecting cattle, sheep, and goats in the southeastern United States are presented. The author's intention is to provide veterinary practitioners and students with an overview of plant poisoning in the region. Plants are grouped by body system affected, based on clinical signs and/or lesions.

Toxic plants of the Northeastern United States.

This article lists commonly encountered toxic plants that affect ruminants in the Northeastern United States. Livestock are at risk for ingestion of a large variety of toxic plants. Plant poisonings are likely to be underdiagnosed because tests for most plant toxins are not routinely available at veterinary diagnostic laboratories. Prevention of access to poisonous plants is usually more effective and economical than treatment of plant poisonings.