Toxins in horses refer to a variety of substances that can cause adverse health effects when ingested, inhaled, or absorbed through the skin. These substances can originate from plants, chemicals, feed contaminants, or environmental sources. Common toxins affecting horses include mycotoxins, heavy metals, and certain plants like ragwort and oleander. Exposure to these toxins can lead to a range of clinical symptoms, from mild discomfort to severe illness or death. Research in this area focuses on identifying toxic agents, understanding their mechanisms of action, and developing strategies for prevention and treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the sources, effects, and management of toxins in equine health.
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.
Carotenuto SE, Broussard G, Fox GA, Hayes WK.To assess the efficacy of a new equine F[ab'] antivenom (US Department of Agriculture code 6101.05) in removing serum venom and lowering the snakebite severity score (SSS) in animals suffering from naturally occurring viperid envenomation. Methods: Retrospective study, April 2020 to October 2021. Methods: Veterinary hospitals across four North American regions. Methods: Twenty-two dogs, one cat, and one horse. Methods: All patients received the new antivenom intravenously and were assessed for clinical response. Most dogs required one vial for clinical control of signs. Results: Among the dogs...
Mohamed E, Van Cleemput J, Şahin B, Van den Broeck W, Boyen F, Nauwynck H.The equine respiratory and reproductive tract microbiomes are complex and subject to constant fluctuations. Among the microbial inhabitants, subsp. (SEZ) is recognized as the dominant bacterium. It is an opportunistic pathogen that may occasionally lead to various types of infections. A key virulence factor of SEZ is the streptolysin S (SLS) toxin, which is responsible for the characteristic β-hemolysis on blood agar and tissue damage. Viruses and bacteria may interact and aggravate lesions and disease. This study aimed to evaluate the impact of an SLS-containing supernatant from SEZ on the...
Kwaß LM, Khiaosa-Ard R, Zebeli Q, Sulyok M, Milojevic V, Metzler-Zebeli BU.The occurrence of biotoxins and chemical residues in marketed horse feeds has direct influences on horse health but has not been studied yet. Objective: The study investigated the exposure and health implications of contaminants in various horse feedstuffs available on the European market. Methods: A total of 108 feed samples representing diverse product categories such as hay, processed roughage products, grains, and various supplementary feeds were collected from different European countries and analyzed for contaminants, including mycotoxins, phytoestrogens, pesticides, and veterinary drug ...
Bauquier J, Takahashi C, Rosales C, Pitt J.There is limited published information on Malva parviflora toxicosis in horses. Four previously reported cases all resulted in death or euthanasia. The aim of this cluster investigation was to describe historical, clinical and clinicopathological findings of four ponies with suspected M. parviflora toxicosis and compare these to previously reported cases. Historical, clinical and clinicopathological findings were collated. Ponies were grazing pasture of approximately >90% M. parviflora. Pony 1 died rapidly without veterinary examination. Pony 2 was examined for prolonged recumbency attribut...
Cserhalmi D, Wermer K.Our paper presents a case study of a Welsh pony mare with grazing-induced severe urticaria. The main clinical signs were eye swelling, depression and extensive urticaria. Physical examination revealed no other abnormalities. Botanical sampling revealed horseweed (Conyza canadensis) as the most abundant species and a potential allergen plant due to sesquiterpene lactones (SQL). Differential diagnosis strongly suggested that the clinical signs were the result of a hypersensitivity reaction to this plant. Former studies brought controversial data about the toxic or allergic potential of horsewee...
Carvalho KS, de Barros CSL, Mendonça FS, Machado M, Riet-Correa F.In Brazil, CNS diseases in equids were little known until the 1980s. Since then, several diagnostic laboratories have been operating in different universities, initially in the South and Southeast regions and, later, in the Central-West, Northeast and North regions. However, the knowledge accumulated from the diagnoses of nervous system diseases of equids made at these institutions over the years has not been reviewed comprehensively, and many papers are published in Portuguese. Here, we review 18 diseases that occur in the nervous system of equids in Brazil, including some critical infectious...
Li X, Hu S, Yu Z, He F, Zhao X, Liu R.Nanoplastics (NPs) are emerging pollutants worldwide. Particularly worrisome is that although studies have reported that NPs can amplify the biotoxicity of environmental pollutants, the specific mechanism remains unclear. Here, we found that NPs, even without significant toxicity (cell survival: 99.11%), amplified the hepatocyte toxicity of Cd. Mechanistically, higher Cd uptake (Δ = 23.80%) combined with crucial intracellular desorption behavior of Cd loaded in NPs (desorption rate: 82.70%) were identified as prerequisites for NPs amplifying Cd cytotoxicity. As for toxigenic pathways, the inf...
Vasconcelos de Sousa AL, Riet-Correa F, Botelho de Castro M, Machado M.We reviewed the history, epidemiology, clinical signs, pathology, pathogenesis, treatment, control, and prophylaxis of Sorghum poisoning in livestock. Economic losses in the livestock industry associated with sorghum have been reported since the 19th century. Hyperacute/acute poisoning associated with cyanide (HCN) or nitrate/nitrite frequently occurs in ruminants that consume high quantities of growth and regrowth sorghum after drought, followed by rainfall, respectively. Chronic cystitis-ataxia syndrome primarily affects horses after weeks of grazing on sorghum pastures, while congenital art...
Dimuccio MM, Ceci E, Bonerba E, Celentano FE, De Marzo P, Leone R, Sportelli S, Bozzo G.The aim of this study was to evaluate cadmium (Cd) concentrations in horses imported from various European Union countries and slaughtered in Italy. In addition, we assessed the potential correlation between Cd levels in tissues and organs, and Cd-related gross and histological lesions. The animals were divided into six groups based on age and geographical origin. Among the 430 animals examined, gross renal lesions were observed in only two kidney samples from Polish horses, which also had the highest Cd concentrations: 9.1 mg/kg w/w and 8.23 mg/kg w/w, respectively. Further histological a...
Karačonji IB, Jelača T, Jurič A, Vrdoljak AL.Opiates such as morphine and codeine are substances often misused to improve the performance of racing horses during competitions and are therefore on the International Federation for Equestrian Sports' list of prohibited substances. However, a positive antidoping test may be due to the consumption of feed (mainly lucerne or oats) contaminated by opium poppy containing the alkaloids morphine and codeine. In order to determine whether a positive antidoping test is the result of an intentional abuse of opiates or consumption of feed contaminated by poppies, we optimised conditions for the extrac...
François AC, Cesarini C, Taminiau B, Renaud B, Kruse CJ, Boemer F, van Loon G, Palmers K, Daube G, Wouters CP, Lecoq L, Gustin P, Votion DM.Hypoglycin A and methylenecyclopropylglycine are protoxins responsible for atypical myopathy in equids. These protoxins are converted into toxins that inhibit fatty acid β-oxidation, leading to blood accumulation of acylcarnitines and toxin conjugates, such as methylenecyclopropylacetyl-carnitine. The enzymes involved in this activation are also present in some prokaryotic cells, raising questions about the potential role of intestinal microbiota in the development of intoxication. Differences have been noted between the faecal microbiota of cograzers and atypical myopathy-affected horses. Ho...
González-Medina S, Hyde C, Chang YM, Piercy RJ.Sycamore tree-derived hypoglycin A (HGA) toxin causes atypical myopathy (AM), an acute, equine pasture-associated rhabdomyolysis but incidence fluctuates. Objective: Investigate whether tree or environmental factors influence HGA concentration in sycamore material and are associated with AM relative risk. Methods: Retrospective and experimental prospective study. Methods: UK sycamore population, seed production and AM incidence data were obtained. HGA concentration was measured in seeds from trees from 10 different central UK locations. The effect of tar spot infection, seed maturity, tree tru...
François AC, Renaud B, Kruse CJ, Marcillaud-Pitel C, Votion DM.Anne-Christine François, Benoît Renaud, Caroline-Julia Kruse, Christel Marcillaud-Pitel and Dominique-Marie Votion of the Atypical Myopathy Alert Group discuss insights from 20 years of research and surveillance on equine atypical myopathy.
Böswald LF, Gottschalk C, Kaltner F, Merk J, Schwaiger K, Kienzle E.While previous reports come mostly from the southern Americas, several outbreaks of hypersalivation in horses were observed in Middle Europe from 2016 to 2018. Objective: To describe feed-induced hypersalivation in European horses. Methods: Analysis of feedstuffs. Methods: Veterinarians and horse or stable owners were encouraged to submit feedstuffs from case outbreaks of hypersalivation in which, infectious diseases or other systemic causes of the syndrome were ruled out and intoxication was suspected. Feedstuff analysis was performed, including gross examination, microscopic analysis of fine...
Renaud B, Kruse CJ, François AC, Cesarini C, van Loon G, Palmers K, Boemer F, Luis G, Gustin P, Votion DM.Equine atypical myopathy (AM) is a severe rhabdomyolysis syndrome primarily caused by hypoglycin A (HGA) and methylenecyclopropylglycine protoxins. This study aimed to refine diagnostic and prognostic criteria for AM while exploring apparently healthy cograzers. Blood samples from 263 horses, including AM cases (n= 95), cograzers (n= 73), colic horses (n= 19), and controls (n= 76), were analyzed for HGA, its toxic metabolite, and acylcarnitines profile. Diseased horses exhibited alterations in acylcarnitines that strongly distinguished them from controls and colic horses. Regression analyses i...
Iranmanesh M, Sato AF, Tenney W, Brinker EJ, Cortez K, Mazan M.A 1-year-old Miniature Horse filly was presented for chronic lethargy and hyporexia. Elevated liver enzymes, bile acids, and ammonia were noted on bloodwork. The primary differential diagnosis was a portosystemic shunt (PSS). Three-phase computed tomographic angiography findings were consistent with a transhepatic portosystemic shunt. Percutaneous liver biopsy confirmed severe diffuse hepatic changes, most likely due to chronic pyrrolizidine alkaloid toxicosis, and medical management was elected. Based on an extensive literature review, this is the first report of a transhepatic portosystemic ...
Morris J, Hoang D.This article discusses a rare case of isolated xylazine overdose in a human, treated successfully with naloxone. Xylazine, typically used as a veterinary tranquilizer, acts as a potent α2 adrenergic agonist, leading to sedation, muscle relaxation, and potential respiratory depression. In this case, a female mistakenly injected herself with xylazine mistaking it for a different medication. The report discusses naloxone's role beyond opioid overdose, especially regarding substances causing central nervous system (CNS) depression via mechanisms similar to those of opioids. While naloxone is trad...
Kruse CJ, Dieu M, Renaud B, François AC, Stern D, Demazy C, Burteau S, Boemer F, Art T, Renard P, Votion DM.Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple (Acer pseudoplatanus) in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy. Label-free proteomic analyses on the serum of 26 diseased AM, 23 cograzers, and 11 control horses were per...
Sander J, Terhardt M, Janzen N, Renaud B, Kruse CJ, François AC, Wouters CP, Boemer F, Votion DM.Equine atypical myopathy is caused by hypoglycin A (HGA) and methylenecyclopropylglycine (MCPrG), the known protoxins of sycamore maple (Acer pseudoplatanus). Various tissues from five atypical myopathy cases were analyzed but only HGA was found. Whether deamination of MCPrG has already occurred in the intestine as the first stage of metabolization has not been investigated. Activation of the protoxins to methylenecyclopropylacetyl (MCPA)-CoA and methylenecyclopropylformyl (MCPF)-CoA, respectively, occurred mainly in the skeletal muscles, as evidenced by very high concentrations of MCPA-carnit...
McCarthy MB, Duesterdieck-Zellmer KF, Larson MK.To determine whether Botulinum neurotoxin type A (BoNT-A) ameliorates the effects of interleukin 1 (IL-1) on equine articular cartilage, or exerts negative effects on normal equine articular cartilage homeostasis in vitro. Methods: Articular cartilage explants from 6 healthy femoropatellar joints of 3 adult horses. Methods: Explants were allocated to the IL-1 challenged or unchallenged group, then exposed to 1 of 6 concentrations of BoNT-A (0, 1, 10, 50, 100, or 500 pg/mL) for 96 hours. To assess BoNT-A's effects on inflammation, prostaglandin E2 (PGE2) was measured in media via ELISA. Matrix ...
Shapter FM, Granados-Soler JL, Stewart AJ, Bertin FR, Allavena R.Crofton weed (Ageratina adenophora) is a global and highly invasive weed, with ingestion causing severe respiratory disease in horses, leading to irreversible and untreatable pulmonary fibrosis and oedema. While reports of equine pneumotoxicity remain common in Australia and New Zealand, equine pneumotoxicity may be underdiagnosed in other countries where Crofton weed is endemic but poorly differentiated. The pathogenesis of Crofton weed toxicity following ingestion has been well described in a number of different animal models, including rodents, rabbits, and goats. However, induced toxicity ...
Fan Y, Lou J, Tam CC, Wen W, Conrad F, Leal da Silva Alves P, Cheng LW, Garcia-Rodriguez C, Farr-Jones S, Marks JD.Equine-derived antitoxin (BAT) is the only treatment for botulism from botulinum neurotoxin serotype G (BoNT/G). BAT is a foreign protein with potentially severe adverse effects and is not renewable. To develop a safe, more potent, and renewable antitoxin, humanized monoclonal antibodies (mAbs) were generated. Yeast displayed single chain Fv (scFv) libraries were prepared from mice immunized with BoNT/G and BoNT/G domains and screened with BoNT/G using fluorescence-activated cell sorting (FACS). Fourteen scFv-binding BoNT/G were isolated with K values ranging from 3.86 nM to 103 nM (median K 2...
Bernardino PN, Pusterla N, Conrad PA, Packham AE, Tamez-Trevino E, Aleman M, James K, Smith WA.Among the recognized neurologic diseases in horses, equine protozoal myeloencephalitis (EPM) has been reported around the world and still presents challenges in diagnosis and treatment. Horses can present with clinical neurologic signs consistent with EPM while testing negative for the two main causative agents, Sarcocystis neurona or Neospora hughesi, and may still be clinically responsive to anti-parasitic drug therapy. This context led to our hypothesis that another protozoal parasite, Toxoplasma gondii, which is known to cause toxoplasmosis in other mammalian species, is a potential pathog...
Schrenk D, Bignami M, Bodin L, Del Mazo JKCJ, Grasl-Kraupp B, Hogstrand C, Leblanc JC, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T....In 2017, 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 deoxynivalenol (DON) and its acetylated and modified forms in food and feed. No observed adverse effect levels (NOAELs) and lowest observed adverse effect levels (LOAELs) were derived for different animal species. For horses, an NOAEL of 36 mg DON/kg feed was established, the highest concentration tested and not showing adverse effects. For poultry, an NOAEL of 5 mg DON/kg feed for broiler chickens and laying hens, and an NOAEL of 7 mg DO...
Cano-Terriza D, Franco JJ, Jose-Cunilleras E, Buono F, Almería S, Veneziano V, Alguacil E, García J, Villena I, Dubey JP, Jiménez-Martín D....Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is a worldwide parasitic zoonosis. A cross-sectional study was carried out to determine the exposure to T. gondii in equids in Europe. Serum samples from 1399 equids (1085 horses, 238 donkeys, and 76 mules/hinnies) bred in four European countries (Italy, Spain, United Kingdom [UK], and Ireland) were collected during the period of 2013-2021. The overall seroprevalence of T. gondii was 18.9% (95% Confidence Interval [CI]: 16.9-21.0) by using the modified agglutination test (MAT) at a cut-off of 1:25. Seropositivity ...
Qi T, Ai J, Sun Y, Ma H, Kang M, You X, Li J.Toxoplasmosis is a zoonotic disease caused by the obligate intracellular protozoan parasite which is widely prevalent in humans and animals worldwide. The diagnosis of toxoplasmosis and distinguishing acute or chronic infections have utmost importance for humans and animals. The SAG1, GRA7, and BAG1 proteins were used in the present study to develop the serological rSAG1-ELISA, rGRA7-ELISA and rBAG1-ELISA methods for the testing of specific IgG and IgM antibodies and differentiating acute or chronic toxoplasmosis in 3733 animals, including Tibetan sheep, yaks, pigs, cows, cattle, horses, ch...
Jahn P, Dobešová D, Brumarová R, Tóthová K, Kopecká A, Friedecký D.Equine atypical myopathy (AM also referred to as multiple acyl-CoA dehydrogenases deficiency [MADD]) is thought to be caused by toxins metabolized from hypoglycin A (HGA) and méthylènecyclopropylglycine (MCPrG). HGA is contained in the seeds and seedlings of the sycamore tree (Acer pseudoplatanus); MCPrG has so far only been confirmed in seeds. Among other things, these substances can disrupt the fatty acids β-oxidation pathway with the subsequent accumulation of certain acylcarnitines. The tentative diagnosis is based on anamnesis and clinical signs and can be verified by the detection of ...
Ben David A, Barnea A, Torgeman A, Diamant E, Dor E, Schwartz A, Rosen O, Caspi N, Saraf M, Lerer E, Adar Y, Lupo E, Toister E, Zichel R.Botulism is a paralytic disease caused by botulinum neurotoxins (BoNTs). Equine antitoxin is currently the standard therapy for botulism in human. The preparation of equine antitoxin relies on the immunization of horses with botulinum toxoid, which suffers from low yield and safety limitations. The Hc fragment of BoNTs was suggested to be a potent antibotulinum subunit vaccine. The current study presents a comparative evaluation of equine-based toxoid-derived antitoxin (TDA) and subunit-derived antitoxin (SDA). The potency of recombinant Hc/A, Hc/B, and Hc/E in mice was similar to that of toxo...
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...
Gelderblom WC, Jaskiewicz K, Marasas WF, Thiel PG, Horak RM, Vleggaar R, Kriek NP.Cultures on corn of Fusarium moniliforme MRC 826 are known to cause leukoencephalomalacia in horses and to be toxic and hepatocarcinogenic in rats. Culture material of this F. moniliforme isolate has also been shown to exhibit cancer-promoting activity in a short-term cancer initiation-promotion bioassay with diethylnitrosamine-initiated rats and the induction of gamma-glutamyl-transpeptidase-positive (GGT+) foci as an endpoint after 4 weeks of promotion. This bioassay was used as a monitoring system to isolate cancer-promoting compounds from cultures of F. moniliforme MRC 826. Culture materia...
Marasas WF, Kellerman TS, Gelderblom WC, Coetzer JA, Thiel PG, van der Lugt JJ.Each of two horses was dosed by stomach tube with culture material on maize of Fusarium moniliforme MRC 826. One horse developed severe hepatosis and mild oedema of the brain after 6 doses of 2.5 g of culture material/kg body mass/day in 7 days. The second horse, in a similar experiment but at a dosage rate of 1.25 g/kg/day, developed mild hepatosis and moderate oedema of the brain. In both animals the brain oedema was particularly noticeable in the medulla oblongata. The mycotoxin fumonisin B1 was extracted and purified from the culture material of F. moniliforme MRC, 826 which contained appr...
Marasas WF.This article describes the events leading to the discovery of the fumonisins in South Africa in 1988 and highlights the first 10 years (1988-1998) of fumonisin research. The predominant fungus isolated from moldy corn implicated in a field outbreak of equine leukoencephalomalacia (ELEM) in South Africa in 1970 was Fusarium verticillioides (F. moniliforme). This fungus was also prevalent in moldy home-grown corn consumed by people in high-incidence areas of esophageal cancer (EC) in the Transkei region of South Africa. Culture material on corn of F. verticillioides strain MRC 826, which was iso...
Kellerman TS, Marasas WF, Thiel PG, Gelderblom WC, Cawood M, Coetzer JA.Leukoencephalomalacia (LEM) was induced by the oral administration of fumonisin B1 (FB1) to 2 horses: a filly received 59.5 mg/kg of a 50% preparation of FB1, administered in 21 doses of 1.25-4 mg/kg over 33 days; a colt, 44.3 mg/kg of 95% pure FB1 in 20 doses of 1-4 mg/kg in 29 days. Both animals developed nervous signs such as apathy, changes in temperament, inco-ordination, walking into objects, and one showed paralysis of the lips and tongue. Characteristic lesions of LEM were present in the brains. These trials proved conclusively that FB1 can induce LEM in horses.
Levy R, Forsyth CM, LaPorte SL, Geren IN, Smith LA, Marks JD.Botulinum neurotoxin (BoNT), the most poisonous substance known, causes naturally occurring human disease (botulism) and is one of the top six biothreat agents. Botulism is treated with polyclonal antibodies produced in horses that are associated with a high incidence of systemic reactions. Human monoclonal antibodies (mAbs) are under development as a safer therapy. Identifying neutralizing epitopes on BoNTs is an important step in generating neutralizing mAbs, and has implications for vaccine development. Here, we show that the three domains of BoNT serotype A (BoNT/A) can be displayed on the...
Ross PF, Nelson PE, Richard JL, Osweiler GD, Rice LG, Plattner RD, Wilson TM.Fumonisin B1 (FB1) and FB2 were isolated from corn cultures of both Fusarium moniliforme and Fusarium proliferatum. Respective concentrations in culture materials of FB1 and FB2 ranged from 960 to 2,350 and 120 to 320 micrograms/g for F. moniliforme and from 1,670 to 2,790 and 150 to 320 micrograms/g for F. proliferatum. Thin-layer chromatography, gas chromatography-mass spectroscopy, high-performance liquid chromatography, and liquid secondary ion mass spectroscopy were used for detection. Fumonisins from F. proliferatum have not previously been reported.
Keel MK, Songer JG.Clostridium difficile is a confirmed pathogen in a wide variety of mammals, but the incidence of disease varies greatly in relation to host species, age, environmental density of spores, administration of antibiotics, and possibly, other factors. Lesions vary as well, in severity and distribution within individuals, and in some instances, age groups, of a given species. The cecum and colon are principally affected in most species, but foals and rabbits develop severe jejunal lesions. Explanations for variable susceptibility of species, and age groups within a species, are largely speculative. ...
Mehdizadeh Gohari I, Parreira VR, Nowell VJ, Nicholson VM, Oliphant K, Prescott JF.A role for type A Clostridium perfringens in acute hemorrhagic and necrotizing gastroenteritis in dogs and in necrotizing enterocolitis of neonatal foals has long been suspected but incompletely characterized. The supernatants of an isolate made from a dog and from a foal that died from these diseases were both found to be highly cytotoxic for an equine ovarian (EO) cell line. Partial genome sequencing of the canine isolate revealed three novel putative toxin genes encoding proteins related to the pore-forming Leukocidin/Hemolysin Superfamily; these were designated netE, netF, and netG. netE a...
Thiel PG, Marasas WF, Sydenham EW, Shephard GS, Gelderblom WC.Contamination of corn with the fungus Fusarium moniliforme and its secondary metabolites, the fumonisins, has been associated with several human and animal diseases. This paper summarizes present knowledge and presents new data on the levels of fumonisins present in foods and feeds associated with these diseases as well as in commercial corn and corn-based products. The doses of fumonisins to which humans and animals consuming these products would be exposed are compared with those doses known to produce LEM in horses and hepatocarcinogenesis in rats. It is concluded that the known naturally o...
Weese JS, Staempfli HR, Prescott JF.Faecal samples from adult horses and from foals with diarrhoea or with normal faeces were evaluated for the presence of Clostridium difficile, C. difficile toxins, C. perfringens enterotoxin (CPE) and C. perfringens spore counts. Clostridium difficile was isolated from 7/55 horses (12.7%) and 11/31 foals (35.5%) with colitis, but from 1/255 normal adults (0.4%) and 0/47 normal foals (P<0.001). Clostridium difficile toxins A and/or B were detected in 12/55 diarrhoeic adults (21.8%) and 5/30 diarrhoeic foals (16.7%) but in only 1/83 adults (1.2%) and 0/21 foals with normal faeces (P<0.001 and P<...
Herholz C, Miserez R, Nicolet J, Frey J, Popoff M, Gibert M, Gerber H, Straub R.The incidence of a new, yet unassigned toxin type of Clostridium perfringens containing the genes for the alpha-toxin and the recently described beta2-toxin in horses with intestinal disorders is reported. The study included 18 horses suffering from typical typhlocolitis, 7 horses with atypical typhlocolitis, 16 horses with other intestinal disorders, and 58 horses without intestinal disease. In total, 20 samples of ingesta of the small and large intestines, five biopsy specimens of the intestinal wall, and 74 fecal samples were analyzed bacteriologically. C. perfringens isolates were typed fo...
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 ...
Diab SS, Kinde H, Moore J, Shahriar MF, Odani J, Anthenill L, Songer G, Uzal FA.Clostridium perfringens type C is an important cause of enteritis and enterocolitis in foals and occasionally in adult horses. The disease is a classic enterotoxemia, and the enteric lesions and systemic effects are caused primarily by beta toxin, 1 of 2 major toxins produced by C. perfringens type C. Until now, only sporadic cases of C. perfringens type C equine enterotoxemia have been reported. We present a comprehensive description of the lesions in 8 confirmed cases of type C enterotoxemia in foals and adult horses. Grossly, multifocal to segmental hemorrhage and thickening of the intestin...
Koop G, Vrieling M, Storisteanu DM, Lok LS, Monie T, van Wigcheren G, Raisen C, Ba X, Gleadall N, Hadjirin N, Timmerman AJ, Wagenaar JA, Klunder HM....Bicomponent pore-forming leukocidins are a family of potent toxins secreted by Staphylococcus aureus, which target white blood cells preferentially and consist of an S- and an F-component. The S-component recognizes a receptor on the host cell, enabling high-affinity binding to the cell surface, after which the toxins form a pore that penetrates the cell lipid bilayer. Until now, six different leukocidins have been described, some of which are host and cell specific. Here, we identify and characterise a novel S. aureus leukocidin; LukPQ. LukPQ is encoded on a 45 kb prophage (ΦSaeq1) found i...
Langan RC, Gotsch PB, Krafczyk MA, Skillinge DD.Ulcerative colitis is a chronic disease with recurrent symptoms and significant morbidity. The precise etiology is still unknown. As many as 25 percent of patients with ulcerative colitis have extraintestinal manifestations. The diagnosis is made endoscopically. Tests such as perinuclear antineutrophilic cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies are promising, but not yet recommended for routine use. Treatment is based on the extent and severity of the disease. Rectal therapy with 5-aminosalicylic acid compounds is used for proctitis. More extensive disease requires t...
Arroyo LG, Kruth SA, Willey BM, Staempfli HR, Low DE, Weese JS.Molecular typing of Clostridium difficile isolates from animals and humans may be useful for evaluation of the possibility for interspecies transmission. The objective of this study was to evaluate C. difficile isolates from domestic animals and humans using PCR ribotyping. Isolates were also tested using PCR for the presence of genes encoding toxins A and B. One hundred and thirty-three isolates of C. difficile from dogs (n = 92), horses (n = 21) and humans (n = 20), plus one each from a cat and a calf, were evaluated. Overall, 23 ribotypes were identified. Of these, nine were identified from...
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...
Ross PF, Rice LG, Osweiler GD, Nelson PE, Richard JL, Wilson TM.During the 1989 corn harvest season, numerous reports of equine leukoencephalomalacia (ELEM) outbreaks and a pulmonary edema (PPE) syndrome in swine from several regions of the United States were received by the National Veterinary Services Laboratories (NVSL), Ames, Iowa. Previous and concurrent research linked Fusarium moniliforme and fumonisin-contaminated feeds to both diseases. Chemical and mycological investigations revealed fumonisin B1 (FB1) concentrations of 20 to 360 ppm in suspect swine feeds and 8 to 117 ppm in suspect equine feeds. Nonproblem feeds contained concentrations below 8...
Hatheway CH, Snyder JD, Seals JE, Edell TA, Lewis GE.Serum levels of equine-botulism antitoxin to toxin types A, B, and E were measured in four type-A botulism patients who had received equine-botulism antitoxin. High circulating levels capable of neutralizing in excess of 1 X 10(8), 9 X 10(7), and 6 X 10(6) 50% mouse lethal doses of toxin of types A, B, and E, respectively, were detected. There was little depletion of type-A antitoxin even though two of the patients had circulating type-A toxin before treatment. The half-life for antitoxin persistence for one patient was calculated as being 6.5, 7.6, and 5.3 days for antitoxin types A, B, and E...
Smith T.The foregoing and earlier data taken together demonstrate that an active immunity lasting several years can be produced in guinea-pigs, by the injection of toxin-antitoxin mixtures which have no recognizable harmful effect either immediate or remote. They also show, what might have been anticipated, that under the same conditions mixtures which produce local lesions and which, therefore, contain an excess of toxin produce a much higher degree of immunity than the neutral mixtures, and that an excess of antitoxin reduces the possibility of producing an active immunity, and may extinguish it alt...
Marasas WF, Kellerman TS, Pienaar JG, Naudé TW.When 2 horses were dosed with cultures of a Fusarium moniliforme isolate that had previously caused only hepatosis, 1 developed brain oedema and hepatosis, and the other only leukoencephalomalacia. A 3rd horse developed both leukoencephalomalacia and hepatosis after being dosed with another isolate obtained from maize which was associated with a natural outbreak of the nervous form of the disease. Since leukoencephalomalacia and hepatosis could be induced by the same culture material, it was concluded that both syndromes were manifestations of the same toxicosis. There was also some evidence t...
de la Rosa G, Olvera F, Archundia IG, Lomonte B, Alagón A, Corzo G.Antivenoms are fundamental in the therapy for snakebites. In elapid venoms, there are toxins, e.g. short-chain α-neurotoxins, which are quite abundant, highly toxic, and consequently play a major role in envenomation processes. The core problem is that such α-neurotoxins are weakly immunogenic, and many current elapid antivenoms show low reactivity towards them. We have previously developed a recombinant consensus short-chain α-neurotoxin (ScNtx) based on sequences from the most lethal elapid venoms from America, Africa, Asia, and Oceania. Here we report that an antivenom generated by immu...
Marasas WF.Fusarium moniliforme is one of the predominant fungi associated with corn intended for human and animal consumption world-wide. Fumonisins, food-borne carcinogens that occur naturally in corn, were first isolated and chemically characterized in South Africa in 1988. The major metabolite, fumonisin B1 (FB1), was subsequently shown to cause leukoencephalomalacia (LEM) in horses, pulmonary edema syndrome (PES) in pigs, and liver cancer in rats. FB1 is also a cancer promoter and initiator in rat liver; hepatotoxic to horses, pigs, rats, and vervet monkeys; cytotoxic to mammalian cell cultures; and...
Villalta M, Pla D, Yang SL, Sanz L, Segura A, Vargas M, Chen PY, Herrera M, Estrada R, Cheng YF, Lee CD, Cerdas M, Chiang JR, Angulo Y, León G....The proteomes of the venoms of the snakes Viridovipera stejnegeri and Protobothrops mucrosquamatus from Taiwan were characterized by N-terminal sequencing, MALDI-TOF mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of in-gel generated tryptic peptides. Proteins belonging to the following toxin classes were identified: metalloproteinase, phospholipase A(2) (PLA(2)), serine proteinase, C-type lectin-like, CRISP, l-amino acid oxidase, disintegrin, and peptides (vasoactive and inhibitors of SVMPs). Nine horses were immunized with a mixture of these venoms. All horse...
Chotwiwatthanakun C, Pratanaphon R, Akesowan S, Sriprapat S, Ratanabanangkoon K.The purpose of this study was to prepare a potent polyvalent antivenom against three elapids namely, the Thai cobra (Naja kaouthia, NK), the King cobra (Ophiophagus hannah, OH) and the banded krait (Bungarus fasciatus, BF). Two groups of horses were immunized. Group 1, comprising five horses, was immunized twice with a mixture of postsynaptic neurotoxins followed by an additional six immunizations with a mixture of crude venoms of the three elapids. Group 2, comprising four horses, was immunized with a mixture of crude venoms throughout the course. For the first immunization, the immunogens we...
Domijan AM.Fumonisin B(1) (FB(1)) is a mycotoxin produced by Fusarium spp. moulds that contaminate crop, predominantly maize, all around the world. More than 15 types of fumonisins have been indentified so far, but FB(1) is the most abundant and toxicologically the most significant one. FB(1) has a wide range of toxic effects, depending on animal species. In horses FB(1) causes equine leukoencephalomalacia (ELEM), in pigs pulmonary oedema and in experimental rodents nephrotoxicity and hepatotoxicity. In humans exposure to FB(1) is linked with higher incidence of primary liver cancer and oesophageal cance...
Wilson TM, Ross PF, Rice LG, Osweiler GD, Nelson HA, Owens DL, Plattner RD, Reggiardo C, Noon TH, Pickrell JW.During the fall of 1989, an episode of equine leukoencephalomalacia involved 18 of 66 purebred Arabian horses at a breeding/training stable in Arizona. Of the 18 horses affected, the condition was fatal in 14. These horses, as well as 48 unaffected horses, had been fed a diet containing a substantial amount of white corn screenings. Gross pathologic findings included liquefactive necrosis in parts of the cerebral white matter and hemorrhagic foci of various sizes in the brain stem. Histopathologic findings included rarefied white matter with pyknotic nuclei and eosinophilic cytoplasm. Thin-lay...
Swanson SP, Helaszek C, Buck WB, Rood HD, Haschek WM.The role of faecal and intestinal microflora on the metabolism of trichothecene mycotoxins was examined in this study. Suspensions of microflora obtained from the faeces of horses, cattle, dogs, rats, swine and chickens were incubated anaerobically with the trichothecene mycotoxin, diacetoxyscirpenol (DAS). Micro-organisms from rats, cattle and swine completely biotransformed DAS, primarily to the deacylated deepoxidation products, deepoxy monoacetoxyscirpenol (DE MAS) and deepoxy scirpentriol (DE SCP). By contrast, faecal microflora from chickens, horses and dogs failed to reduce the epoxide ...
