Toxicology in horses involves the study of substances that can cause adverse effects when introduced to the equine body. This field examines the sources, mechanisms, and outcomes of exposure to toxic agents, which may include plants, chemicals, drugs, and environmental toxins. Understanding toxicology is essential for identifying and managing poisoning cases in horses. Research in this area often focuses on the identification of toxic compounds, their metabolic pathways, and the clinical symptoms associated with exposure. This page compiles peer-reviewed research studies and scholarly articles that explore the detection, effects, and management of toxic substances in equine health.
Guan F, Adreance MA, Fay S, McGoldrick LK, Keen B, You Y, Robinson MA.Hypoxia-inducible factor (HIF) activating agents can promote the transcription of the erythropoietin gene, enhancing an athlete's performance, and are therefore prohibited in sports. A liquid chromatography coupled to high-resolution mass spectrometry (LCHRMS) method was developed for the detection and confirmation of 11 HIF-activating substances in equine plasma and urine. Ammonium formate added to the mobile phase system suppressed the responses of all the analytes in either positive or negative ion mode and thus was not used. The starting organic percentage in the mobile phase gradient and ...
Yamashita N, Yoshihara T, Hatazoe T, Misumi K, Hobo S.We investigated the health of Tokara horses (n=34) on Nakanoshima as part of conservation efforts for this breed. Although the horses were clinically healthy, elevated white blood cell count, neutrophil count and gamma-glutamyl transferase (GGT) levels were observed, leading to suspicion of chronic hepatic dysfunction and infectious disease. A survey revealed that the caretakers had been feeding the horses Leopard plant, which contains toxic pyrrolizidine alkaloids (PAs). The abnormal GGT levels observed in these horses may suggest the possibility of chronic PA poisoning resulting from the con...
Summers KM, Karagianni AE, Fernandez PL, Beard PM, Pirie RS, Keen JA, Wishart TM, McGorum BC.Equine grass sickness (EGS or equine dysautonomia) is a predominantly fatal multi-system neuropathy affecting grazing horses, likely caused by a neurotoxic phospholipase A2 (nPLA2) derived from a plant or microorganism. We studied neuronal tissue gene and protein expression patterns in EGS to elucidate the possible mechanisms of neurotoxicity and neurodegeneration. Tissue from the cranial cervical ganglion of eight EGS horses and six controls was examined histologically and used for transcriptomic analysis. These transcriptomic data were compared with previously published EGS-related proteomic...
Silveira AM, Mendonça MFF, Oliveira Filho JC, Caymmi LG, Pimentel LA, Riet-Correa F.This paper reports an outbreak of Chamaecrista serpens var. serpens poisoning in Mangalarga Marchador horses, Pega donkeys, Nelore cattle, and Mambrina goats. The disease occurred in the municipality of Iaçu, in the semi-arid region of the state of Bahia, 15-30 days after the start of the rainy season, coinciding with the regrowth of the plant. The prevalence of the poisoning was 100% in donkeys and horses, 11.9% in cattle, and 38.8% in goats. Clinical signs were characterized by itching, edema, and crust formation, predominantly in areas of non-pigmented skin or with less hair coverage and i...
Lynch AD, Mama KR, McKemie DS, Kass PH, Knych HK.Tapentadol is a dual mechanism analgesic utilizing both μ-opioid receptor (MOR) agonism and norepinephrine reuptake inhibition (NRI). This study evaluated the pharmacokinetics and pharmacodynamics of tapentadol as a potential analgesic with the goal of treating pain in horses. Pharmacokinetics of both tapentadol and tapentadol-O-glucuronide were elucidated. Six horses received three separate escalating single oral doses (1, 3, and 5 mg/kg) and a single intravenous (0.32 mg/kg) dose of tapentadol in a four-period sequential design. Concentrations of tapentadol and tapentadol-O-glucuronide ...
Hulitká D, Coradduzza D, Sanna A, Biggio GP, Taras A, Cannas A, Carru C, Medici S, Cherchi R, Cappai MG.Bone tissue undergoes continuous remodelling throughout the life of the individual, and growth is the most impacting phase. In fact, tightly coordinated processes of resorption, synthesis, and mineralization of the bone matrix under systemic hormonal, biomechanical, and metabolic control occur for variable periods of time across species. The horse is a fast-growing animal and for this reason identified as precocial. It was hypothesized that blood serum levels of minerals in growing foals at different stages of accretion may vary over time. This investigation aimed to assess the dynamics of cir...
El Abbadi I, Pallier V, Bastos MC, Lissalde S, Feuillade G.This study developed a method for the simultaneous quantification of six potentially environmentally toxic veterinary drugs: benzylpenicillin, acepromazine, flunixin, dexamethasone, ketamine and romifidine, in soils, sediments, equine faeces and natural waters. Three methods were compared for their extraction from solid matrices: Ultrasonic extraction (USE), QuEChERS and Accelerated Solvent Extraction (ASE). ASE method was optimized according to temperature and extraction cycles. Quantification was performed by LC-MS/MS. LC and MS parameters were optimized. The method was validated according t...
Diab SS, Giannitti F, Hill A, Morgan J, Blea JA, Arthur R, Poppenga R, Stover S, Uzal FA.Horse racing has faced increased scrutiny because of concerns about equine welfare and the safety of both equine and human participants. Sudden death (SD) in racehorses is relatively uncommon, and its causes are still unclear. Little information and considerable confusion exist regarding the clinical significance of microscopic lesions in the hearts of horses with SD. We examined the hearts of 29 horses that suffered exercise-associated sudden cardiac death (EASCD) and 29 clinically healthy control horses that were euthanized because of catastrophic musculoskeletal injuries. Acute cardiomyocyt...
Ekstrand C, Michanek P, Hernlund E, Gehring R, Salomonsson M.Cannabidiol (CBD) and cannabidiolic acid (CBDA) are non-psychoactive cannabinoids naturally present in hemp-derived products. While these compounds are prohibited during equine competition, horses may be inadvertently exposed through contaminated feed. Data describing systemic and urinary exposure to CBD and CBDA following such low-dose, involuntary intake are limited. This study aimed to describe plasma and urine concentration-time profiles of CBD and CBDA in horses after consumption of experimentally contaminated feed. Results: Twelve Standardbred horses received feed containing low doses (1...
Uzal FA, Asin J, Diab S, Henderson E, Engiles JB, Kennedy L, Schild C.Sudden death (SD) is the second most important syndrome associated with death in racehorses. The cause of SD in a large number of horses remains undetermined, and, in many of these cases, causes are not found by gross or microscopic postmortem examinations. Among the known causes of SD are traumatic injuries, including fractures of skull, neck, and pelvis; intoxications (e.g., anticoagulant rodenticides); and others. For many cases of SD in which no significant lesions are found, heart failure, probably associated with arrhythmias, is suspected. Precise phenotypic characterization of SD in hor...
Kadláčková M, Dobešová D, Ivanovová E, Masař R, Jahn P, Šamonilová E, Friedecký D, Brumarová R.Atypical myopathy (AM) is a frequently fatal, toxin-induced disease in horses, characterised by acute progression and mortality rates exceeding 70% within 72 h. The disease is caused by ingestion of seedlings or seeds of certain maple species that contain the toxins hypoglycin A (HGA) and methylenecyclopropylglycine (MCPrG). Early diagnosis depends on reliable detection of these compounds and their metabolites. However, most available LC-MS/MS assays are limited by derivatisation requirements and dependence on serum and urine matrices. Here, a rapid derivatisation-free flow injection analysis...
Jacobs ME, Blea J, Hardy M, McKemie DS, Traynham M, Knych HK.Metformin is a diabetes medication with minimal therapeutic efficacy in veterinary medicine. However, recently there have been several adverse analytical findings in regulatory samples collected from racehorses. Metformin is commonly prescribed to humans, is excreted unchanged in urine, and is resistant to environmental degradation, raising concerns with respect to environmental contamination. In this study, six horses were exposed to shavings contaminated with metformin-positive urine at concentrations of 10, 135, and 270 μg/mL. Blood (plasma, serum, whole blood, and red blood cells) and u...
Ribeiro GSN, de Souza AF, Campos ML, Fonteque JH.Trace elements arsenic, cadmium, lead, chromium, mercury, nickel, and zinc are high-density, naturally occurring metals notable for their toxicity and environmental persistence. Cadmium and mercury are particularly concerning due to their capacity for bioaccumulation and biomagnification within the food chain. Dispersed through both anthropogenic and natural sources, these elements pose significant threats to ecosystems and animal health. In equines, they induce oxidative stress by disrupting mitochondrial function, generating reactive oxygen species, and inhibiting antioxidant enzymes, leadin...
Kabil E, Ural MN, Göktaş EF.Synthetic cannabinoids (SCs) were originally synthesized to advance the understanding of the endocannabinoid system, facilitate disease research, and support the development of novel therapeutic agents. Compared with tetrahydrocannabinol, these compounds exhibit substantially higher psychoactive potency and enhanced receptor-binding affinity. The rapid and continuous evolution of SC derivatives presents significant challenges for analytical laboratories and increases the risk of misuse. Furthermore, SCs may be exploited to alter performance in both human and animal sports. The scarcity of comp...
Sakai DM, Ishikawa Y, Im JSY, Zhang S, Reed RA, Quandt JE, Barletta M, Knych HK.Administering large volumes of bupivacaine in the rectus abdominis sheath (RAS) block in horses could cause local anesthetic toxicity. This study aimed to evaluate the pharmacokinetics of 2 mg/kg bupivacaine in RAS blocks and the associated toxicity risk. Six healthy adult horses were sedated with xylazine and received an ultrasound-guided bilateral 2-point RAS block. Plasma samples were collected at baseline and from 5 min to 24 h after the block and analyzed using liquid chromatography-tandem mass spectrometry. A noncompartmental analysis was performed to determine the maximum concentr...
Aguirre Siliezar K, Datu C, Proia K, Rotstein D, Nemser SM, Tyson GH, Ragsdale JM, Wilkes RP, Baker RE, Carossino M, Del Piero F, Sasaki E, Yant P....A multi-state outbreak of equine botulism occurred between December 2022 and March 2023 in the United States. Follow-up and testing were performed on 42 horses, including 24 that died or were euthanized in the outbreak that affected ~98 horses. Affected horses had all been exposed to the same commercial feed. Clinical signs included progressive muscle weakness and tremors, recumbency, and colic. No significant gross or microscopic abnormalities were observed on autopsy. Feces and gastrointestinal content were tested for various infectious agents, including botulinum toxin; fecal samples from 2...
Wickizer LF, Burk SV, Lehman JS.Red maple toxicosis arises when horses consume wilted maple leaves, resulting in methemoglobinemia and hemolytic anemia due to oxidative damage to erythrocytes. Objective: The objective of this study was to determine how maple species (red versus Freeman maple) and horse characteristics, management, and barn site contributed to in vitro methemoglobin production and hemolysis. Methods: Horse information was obtained through an owner questionnaire. Extracts from red and Freeman maple leaves were separately incubated with washed erythrocytes from each horse (n=120). The in vitro percentage methem...
So YM, Kwok WH, Yuen SMS, Wong COL, Ho ENM.Despite the recent success in introducing supramolecular solvents (SUPRAS)-based extraction to drug analysis, its application and robustness in day-to-day regular urine testing have yet to be demonstrated. Moreover, the applicability of SUPRAS in equine doping control testing remains unexplored. In this work, we have successfully developed for the first time a simple, rapid, inexpensive, and environmentally friendly SUPRAS extraction method for analyzing 76 prohibited substances of different classes (selective androgen receptor modulators, hypoxia-inducible factor prolyl hydroxylase inhibitors...
Marcelino I, Monti G, Cornelissen P, Bassingthwaighte E, Het Lam J, van der Merwe D, van der Poel WHM.Trace minerals are essential for animal health but can also, together with heavy metals, have a negative impact, making their monitoring crucial to assess animal health. These elements were examined through a long-term post-mortem monitoring system based on routine liver sampling for Heck cattle, Konik horses and red deer in place at the Oostvaardersplassen nature reserve in the Netherlands, using data from this system to determine reference intervals and investigate trends in liver trace element concentrations. Throughout the monitoring programme, inductively coupled plasma mass spectrometry ...
Zebeli Q, Lindner L, Metzler-Zebeli BU.Grasslands are the cornerstone of horse feeding, used for grazing and to produce roughages and their products. However, improper grassland management hides several threats for equine health. In this context, grasslands contaminated with toxin-producing endophytes are considered an increasing threat for horses in many parts of the world. Endophytes are fungi that may grow in a mutualistic relationship in a range of grasses, including fescue grass and perennial ryegrass, two foliage species commonly found in European and American meadows and pastures. The endophytes produce alkaloids that are hi...
Andrade AC, Fonseca SMC, Silva Filho GB, Melo ET, Santos JRP, Frota MLSL, Duarte JMBS, Evêncio-Neto J, Brito LB, Lima TS, Wicpolt NS, Riet-Correa F....We report an outbreak of Crotalaria juncea intoxication in horses exhibiting progressive weight loss and respiratory distress in northeastern Brazil. Necropsy revealed firm, non-collapsed lungs with extensive interstitial fibrosis, bronchiolar epithelial hyperplasia with club cells proliferation, and marked pulmonary arterial remodeling. Hepatic lesions consisted primarily of centrilobular necrosis, probably resulting from hypoxic injury related to anemia and prolonged agonic death. Pasture inspection identified significant invasion by shrubs of C. juncea in various phenological stages.
Cardillo NN, Villarino NF, Kappmeyer LS, Chung CJ, Suarez CE, Bastos RG.Equine piroplasmosis (EP) is a tick-borne disease of equids caused by the intraerythrocytic apicomplexan parasites Theileria equi, Babesia caballi and the recently identified Theileria haneyi. Acute cases can be severe, with anemia, jaundice, abortion or sudden death. Survivors remain lifelong carriers, serving as reservoirs for tick-borne and iatrogenic transmission. No vaccines are currently available, and control strategies rely heavily on accurate diagnostics and chemotherapeutic intervention. Imidocarb dipropionate (ID) is the current standard of care for both acute treatment and radical ...
Riet-Correa F, Micheloud JF, Machado M, Mendonça FS, Schild AL, Uzal FA, Lemos RAA.The objective of this paper is to review the information on toxic plants for ruminants and horses in South America, a continent in which there are 237 plants known to be toxic for livestock. Predisposing factors for plant toxicity include parts or vegetative state of the plants consumed, sprouting after rains, toxic dose, social facilitation, palatability, hunger, thirst, naivete, ingestion period, susceptibility/resistance, transportation, climatic alterations, and environmental degradation. Toxic plants can be forage or non-forage species. The latter can be invasive plants from other regions...
Gupta KK, Singh L, Saxena N, Dey S, Kumar R, Kumar S.Equine piroplasmosis is a tick-borne disease that affects horses and is caused by Theileria equi and Babesia caballi. Currently, imidocarb dipropionate is the primary treatment for T. equi infections; however, its application is limited by its potential systemic toxicity. Artemisia annua is widely recognised for its antimalarial properties, whereas Artemisia scoparia has traditionally been used for various medicinal purposes. However, the therapeutic potential of A. scoparia against theileriosis in animals remains largely unknown. Activity-guided fractionation of a methanolic extract of A. sco...
Riquelme LF, de Araújo VO, da Silva TKF, de Sousa MS, da Silva MA, da Silva WDQ, Lucena RB.Malachra fasciata Jacq. (Malvaceae) is an invasive plant widely found in Northeastern Brazil and has been experimentally demonstrated to cause severe dermatitis in sheep. However, its toxic effects in horses have not previously been documented. This report describes primary photosensitization in four Quarter Horses grazing on a pasture heavily infested with M. fasciata in Paraíba, Brazil. Affected animals developed alopecic, erythematous, crusted, and ulcerated lesions on sun-exposed areas, accompanied by severe pruritus and behavioral signs of distress. Histopathology revealed epidermal ulce...
Environmental contamination with heavy metals, resulting from industrialization, urbanization, and agricultural intensification, poses serious ecological and health risks. Horses, due to their grazing behavior and close association with human environments, serve as reliable sentinel species for assessing environmental pollution. This study aimed to evaluate the bioaccumulation of heavy metals and trace elements in different biological matrices of horses-blood, hair, hooves, and synovial fluid-and to investigate their relationship with hematological biomarkers as indicators of physiological str...
Pereira GF, Blimbliem MCH, Machado ALPR, Abdala JBR, Nogueira GM, Toma HS, de Carvalho TF, Delfiol DJZ.Arsenic poisoning in horses is rarely reported in the literature. However, arsenic compounds can be present in rodenticides, pesticides, and herbicides, representing a potential source of accidental exposure for horses. Objective: To describe the epidemiological, clinical, and laboratory findings from a herd of 31 horses exposed to pasture treated with an overdose of sodium hydrogen methylarsonate, and to compare results in a group of horses exposed to the recommended dosage of the same product. Methods: Observational field study. Methods: Thirty-one horses were evaluated after grazing on a pa...
François AC, Taminiau B, Renaud B, Gonza-Quito IE, Massey C, Hyde C, Piercy RJ, Douny C, Scippo ML, Daube G, Gustin P, Delcenserie V, Votion DM.Hypoglycin A is a plant-derived protoxin that causes atypical myopathy in equids. In atypical myopathy-affected horses, metabolomic and microbiome studies have reported alterations in metabolic markers and faecal microbiota composition, pointing to a potential disruption of microbial homeostasis. However, in vivo observations are strongly confounded by host-related factors, underscoring the need for controlled in vitro approaches. To address this, we used an in vitro static batch fermentation model simulating the equine colon to investigate the direct effects of hypoglycin A on microbiota comp...
Janzen N, Sander J, Terhardt M, Mallek M, Smith H, Witt P, Theelen MJP.The case of a young foal poisoned by maple toxin is described. It showed signs of myopathy caused by ingesting life-threatening amounts of maple toxin. Some maple trees (Acer species) can pose a health risk to grazing horses. The leaves, seeds and shoots contain hypoglycin A (HGA) and methylencyclopropylglycine (MCPRG) and can cause life-threatening atypical myopathy.
Barabas K, Milner R, Lurie D, Adin C.Cisplatin is a platinum chemotherapeutic used in a variety of malignancies. The antineoplastic activity occurs from DNA cross-links and adducts, in addition to the generation of superoxide radicals. Nephrotoxicity is the most well-known and potentially most clinically significant toxicity. Unfortunately, the mechanism for cisplatin nephrotoxicity has not been completely elucidated; however, many theories have been developed. Other toxicities include gastrointestinal, myelosuppression, ototoxicity and neurotoxicity. Saline diuresis is currently the most accepted way to prevent cisplatin nephrot...
Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C....Zearalenone (ZEN), a mycotoxin primarily produced by Fusarium fungi, occurs predominantly in cereal grains. The European Commission asked EFSA for a scientific opinion on the risk to animal health related to ZEN and its modified forms in feed. Modified forms of ZEN occurring in feed include phase I metabolites α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL), zearalanone (ZAN) and phase II conjugates. ZEN has oestrogenic activity and the oestrogenic activity of the modified forms of ZEN differs considerably. For ZEN, the EFSA Panel on Contaminants...
Schmoldt A, Benthe HF, Haberland G, Jallon JM, Risler Y, Iwatsubo M, Karuzina II, Bachmanova GI, Kuznetsova GP, Izotov MV, Archakov AI, Kröger H....It has been found that NADPH-dependent hydroxylation of dimethylaniline, aniline, p- and o-nitroanisol and lipid peroxidation is inhibited by the tyrosine-copper (II) complex (low molecular weight analog of superoxide dismutase), which is indicative of a possibility of superoxide radicals formation in these reactions. The inhibition of the above-mentioned reactions with Tyr2-Cu2+ is less pronounced or absent, if cumole hydroperoxide is used as cosubstrate instead of NADPH. Differences in the Tyr2-Cu2+ complex effects on the cumule hydroperoxide-dependent xenobiotics hydroxylation and lipid per...
Brayton CF.Dimethyl sulfoxide (DMSO) is a very simple compound that has stimulated much controversy in the scientific and popular literature. Fig. 1 It is an aprotic solvent. Therapeutic and toxic agents that are not soluble in water are often soluble in DMSO. DMSO has a very strong affinity for water; on exposure to air, pure DMSO is rapidly diluted. DMSO's physiologic and pharmacologic properties and effects are incompletely understood. Properties that are considered to be particularly important to its therapeutic and toxic effects include: its own rapid penetration and enhanced penetration of other su...
Lees P, Landoni MF, Giraudel J, Toutain PL.This review summarises selected aspects of the pharmacokinetics (PK) and pharmacodynamics (PD) of nonsteroidal anti-inflammatory drugs (NSAIDs). It is not intended to be comprehensive, in that it covers neither minor species nor several important aspects of NSAID PD. The limited objective of the review is to summarise those aspects of NSAID PK and PD, which are important to an understanding of PK-PD integration and PK-PD modelling (the subject of the next review in this issue). The general features of NSAID PK are: usually good bioavailability from oral, intramuscular and subcutaneous administ...
Kriek NP, Kellerman TS, Marasas WF.An isolate of Fusarium verticillioides (MRC826) that induced experimental leukoencephalomalacia, also caused acute toxicity when fed to pigs and administered per rumen fistula to sheep. Pigs developed severe pulmonary oedema while sheep manifested severe nephrosis and hepatosis. A less toxic isolate (F. verticillioides MRC602), fed to baboons, resulted in acute congestive heart failure or hepatic cirrhosis, depending on the dose. Both isolates were toxic to rats and caused similar lesions, namely, hepatic cirrhosis and intraventricular cardiac thrombosis.
Berny P, Caloni F, Croubels S, Sachana M, Vandenbroucke V, Davanzo F, Guitart R.This is the second in a series of three review articles on animal poisoning in Europe and focuses on cases in pet animals and horses in five European countries (Belgium, France, Greece, Italy and Spain) reported over the last decade. In the participating countries, dogs were the most commonly poisoned species, particularly younger animals. The majority of cases in companion animals resulted from exposure to insecticides, although rodenticides (especially anticoagulants and strychnine) posed a significant risk. In all five countries, horses and cats appeared to be more susceptible to plant toxi...
Benachour N, Sipahutar H, Moslemi S, Gasnier C, Travert C, Séralini GE.Roundup is the major herbicide used worldwide, in particular on genetically modified plants that have been designed to tolerate it. We have tested the toxicity and endocrine disruption potential of Roundup (Bioforce on human embryonic 293 and placental-derived JEG3 cells, but also on normal human placenta and equine testis. The cell lines have proven to be suitable to estimate hormonal activity and toxicity of pollutants. The median lethal dose (LD(50)) of Roundup with embryonic cells is 0.3% within 1 h in serum-free medium, and it decreases to reach 0.06% (containing among other compounds 1.2...
Ambruosi B, Uranio MF, Sardanelli AM, Pocar P, Martino NA, Paternoster MS, Amati F, Dell'Aquila ME.Phthalates are ubiquitous environmental contaminants because of their use in plastics and other common consumer products. Di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate and it impairs fertility by acting as an endocrine disruptor. The aim of the present study was to analyze the effects of in vitro acute exposure to DEHP on oocyte maturation, energy and oxidative status in the horse, a large animal model. Cumulus cell (CC) apoptosis and oxidative status were also investigated. Cumulus-oocyte complexes from the ovaries of slaughtered mares were cultured in vitro in presence of...
Bide RW, Armour SJ, Yee E.The relationship between body weight (BW) and respiratory minute volume (V(m)) was reviewed by collecting a database from the literature. The data were separated into anaesthetized and non-anaesthetized groups. Only young adult terrestrial mammals were included in the final data set. This database is the largest to be reported to date, is the first to separate the anaesthetized and non-anaesthetized groups and is matched to the target population of young, fit adult humans. The data set of non-anaesthetized animals contained 142 studies representing 2616 animals and 18 species from mice at 12 g...
Thiel PG, Marasas WF, Sydenham EW, Shephard GS, Gelderblom WC, Nieuwenhuis JJ.Fumonisins B1 (FB1) and B2 (FB2), two structurally related mycotoxins with cancer-promoting activity, were recently isolated from corn cultures of Fusarium moniliforme MRC 826. These toxins have been reported to be produced also by isolates of F. proliferatum. Contamination of foods and feeds by F. moniliforme has been associated with human esophageal cancer risk, and FB1 has been shown to be the causative agent of the neurotoxic disease leukoencephalomalacia in horses. Because of the toxicological importance of the fumonisins, the potential to produce FB1 and FB2 was determined in a study of ...
Valberg SJ, Sponseller BT, Hegeman AD, Earing J, Bender JB, Martinson KL, Patterson SE, Sweetman L.We hypothesised that seasonal pasture myopathy (SPM), which closely resembles atypical myopathy (AM), was caused by ingestion of a seed-bearing plant abundant in autumn pastures. Objective: To identify a common seed-bearing plant among autumn pastures of horses with SPM, and to determine whether the toxic amino acid hypoglycin A was present in the seeds and whether hypoglycin metabolites were present in SPM horse serum or urine. Methods: Twelve SPM cases, 11 SPM pastures and 23 control farms were visited to identify a plant common to all SPM farms in autumn. A common seed was analysed for amin...
MacAllister CG, Morgan SJ, Borne AT, Pollet RA.The relative toxicity of phenylbutazone, flunixin meglumine, and ketoprofen was studied in healthy adult horses. Sixteen horses were randomly assigned to receive 10 ml of physiologic saline solution, or ketoprofen (2.2 mg/kg of body weight), flunixin meglumine (1.1 mg/kg), or phenylbutazone (4.4 mg/kg) IV, every 8 hours, for 12 days. Results of CBC, serum biochemical analyses, and fecal occult blood tests were monitored. On day 13, all horses were euthanatized and complete necropsy examinations were performed. Mean CBC values remained within normal limits for all groups. Phenylbutazone-treated...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Fašmon Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A....Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of olibanum extract from Roxb. ex Colebr., when used as a sensory additive (flavouring) in feed for all dogs and horses. The FEEDAP Panel concluded that the additive under assessment is safe for horses at the maximum proposed use level of 100 mg/kg in complete feed. For dogs, the calculated safe concentration in feed is 330 mg/kg complete feed. The additive is considered safe for consumers...
Bochnia M, Ziegler J, Sander J, Uhlig A, Schaefer S, Vollstedt S, Glatter M, Abel S, Recknagel S, Schusser GF, Wensch-Dorendorf M, Zeyner A.Hypoglycin A (HGA) in seeds of Acer spp. is suspected to cause seasonal pasture myopathy in North America and equine atypical myopathy (AM) in Europe, fatal diseases in horses on pasture. In previous studies, this suspicion was substantiated by the correlation of seed HGA content with the concentrations of toxic metabolites in urine and serum (MCPA-conjugates) of affected horses. However, seed sampling was conducted after rather than during an outbreak of the disease. The aim of this study was to further confirm the causality between HGA occurrence and disease outbreak by seed sampling during ...
Serra M, Papakonstantinou S, Adamcova M, O'Brien PJ.The use of cardiac troponin (cTn), the 'gold-standard' biomarker of myocardial injury in humans, is growing in veterinary medicine and in animal safety studies, although there are differences in its application in animals. In this study six new assays for the marker were assessed in 619 animals of six different species (dog, cat, horse, cattle, rat and rabbit), in clinical and drug-safety studies. Healthy animals and clinical cases without cardiac disease served as controls. Several of the tested assays had poor analytic or diagnostic sensitivity and only one test was effective in all species ...
Caloni F, Cortinovis C, Rivolta M, Davanzo F.A retrospective study was carried out by reviewing all suspected cases of domestic animal poisoning attributed to pesticides, reported to the Milan Poison Control Centre (MPCC) between January 2011 and December 2013. During this period, pesticides were found to be responsible for 37.3% of all suspected poisoning enquiries received (815). The most commonly species involved was the dog (71.1% of calls) followed by the cat (15.8%), while a limited number of cases involved horses, goats and sheep. Most cases of exposure (47.1%) resulted in mild to moderate clinical signs. The outcome was reported ...
Voss KA, Norred WP, Plattner RD, Bacon CW.Currently there is no convenient bioassay to determine the potential toxicity of corn naturally contaminated with Fusarium moniliforme. A short-term bioassay would be useful for future investigations aimed at isolating as yet unidentified toxins produced by this fungus. Two groups of five male Sprague-Dawley rats were each fed one of two F. moniliforme contaminated corn samples, designated CS-1 and CS-2, that were associated with separate field cases of equine leukoencephalomalacia (ELEM). A control group, also consisting of five male rats, was fed uncontaminated seed corn. All animals survive...
Votion DM, van Galen G, Sweetman L, Boemer F, de Tullio P, Dopagne C, Lefère L, Mouithys-Mickalad A, Patarin F, Rouxhet S, van Loon G, Serteyn D....It is hypothesised that European atypical myopathy (AM) has a similar basis as seasonal pasture myopathy in North America, which is now known to be caused by ingestion of hypoglycin A contained in seeds from the tree Acer negundo. Serum from horses with seasonal pasture myopathy contained the conjugated toxic metabolite of hypoglycin A, methylenecyclopropyl acetic acid (MCPA). Methods: Retrospective study on archived samples. Objective: 1) To determine whether MCPA-carnitine was present in serum of European horses confirmed to have AM; 2) to determine whether Acer negundo or related Acer speci...
Schrenk D, Bignami M, Bodin L, Chipman JK, Del Mazo J, Grasl-Kraupp B, Hogstrand C, Leblanc JC, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T....In 2018, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed. A no observed adverse effect level (NOAEL) of 1 mg/kg feed was established for pigs. In poultry a NOAEL of 20 mg/kg feed and in horses a reference point for adverse animal health effect of 8.8 mg/kg feed was established, referred to as NOAEL. The European Commission (EC) requested EFSA to review the information regarding the toxicity of fumonisins for pigs, poultry and horses an...
The Journal of nutritionAugust 11, 1992
Volume 122, Issue 8 1706-1716 doi: 10.1093/jn/122.8.1706
Wang E, Ross PF, Wilson TM, Riley RT, Merrill AH.Consumption of food contaminated with Fusarium moniliforme causes leucoencephalomalacia and hepatotoxicity in horses, pulmonary edema in pigs and liver cancer in rats, and has been correlated with esophageal cancer in humans. The causative agents are thought to be a family of compounds called fumonisins, which have recently been shown to be potent inhibitors of sphingosine (sphinganine) N-acyltransferase. Because inhibition at this step blocks the formation of complex sphingolipids while leading to accumulation of sphinganine, we hypothesized that exposure of animals to fumonisin-contaminated ...
The Journal of nutritionMay 1, 1997
Volume 127, Issue 5 Suppl 830S-833S doi: 10.1093/jn/127.5.830S
Merrill AH, Schmelz EM, Wang E, Dillehay DL, Rice LG, Meredith F, Riley RT.Sphingolipids are highly bioactive compounds that participate in the regulation of cell growth, differentiation, diverse cell functions, and apoptosis. They are present in both plant and animal foods in appreciable amounts, but little is known about their nutritional significance. Recent studies have shown that feeding sphingomyelin to female CF1 mice treated with a colon carcinogen (1,2-dimethylhydrazine) reduced the number of aberrant colonic crypt foci; longer-term feeding also affected the appearance of colonic adenocarcinomas. Therefore, dietary sphingolipids should be considered in studi...
Filannino A, Stout TA, Gadella BM, Sostaric E, Pizzi F, Colenbrander B, Dell'Aquila ME, Minervini F.The aim of this study was to investigate the in vitro effects of the Fusarium fungus-derived mycotoxin, zearalenone and its derivatives alpha-zearalenol and beta-zearalenol on motility parameters and the acrosome reaction of stallion sperm. Since the toxic effects of zearalenone and its derivatives are thought to result from their structural similarity to 17beta-estradiol, 17beta-estradiol was used as a positive control for 'estrogen-like' effects. Methods: Stallion spermatozoa were exposed in vitro to zearalenone, alpha-zearalenol, beta-zearalenol or 17beta-estradiol at concentrations ranging...
Lees P, Higgins AJ.Weak organic acids possessing anti-inflammatory, analgesic and antipyretic properties--commonly known as aspirin-like drugs--have been used in equine medicine for almost 100 years. These non-steroidal anti-inflammatory drugs (NSAIDs) may be classified chemically into two groups; the enolic acids such as phenylbutazone and carboxylic acids like flunixin, meclofenamate and naproxen. All NSAIDs have similar and possibly identical modes of action accounting for both their therapeutic and their toxic effects. They block some part of the cyclo-oxygenase enzyme pathway and thereby suppress the synthe...
Farmer AA, Farmer AM.This paper presents results of analysis of animal feed and meat (cattle, horse and sheep) products from a metal processing region (Oskemen) in east Kazakhstan. Samples were collected from a range of districts of differing distances from the main source of anthropogenic pollution and with differing underlying metal-containing geologies. Analyses for cadmium, lead and zinc revealed high concentrations in many feed and meat samples. Horse (an important food animal) samples had higher levels of contamination than cattle, which were higher than sheep. For example, mean cadmium concentrations in hor...
Oelrichs PB, Calanasan CA, MacLeod JK, Seawright AA, Ng JC.Regular ingestion of Eupatorium adenophorum [Ageratina adenophora (Spreng.)] or Crofton weed causes chronic pulmonary disease in horses mainly in Australia, New Zealand, and the Himalayas. The disease is characterized by pulmonary interstitial fibrosis, emphysema, alveolar epithelisation and reduced tolerance to exercise. Horses apparently are the only animals affected and there are numerous reports of farms losing all their horses. The disorder was produced experimentally in horse feeding trials, and it was shown that characteristic lesions occurred in the lungs. In studies with laboratory an...
