Toxic plants are a concern in equine management as they pose health risks to horses when ingested. These plants contain various compounds that can lead to adverse effects ranging from mild discomfort to severe illness or death. Horses may encounter toxic plants in pastures, hay, or during foraging. Common toxic plants include ragwort, yew, and oleander, each containing specific toxins that affect equine physiology differently. Understanding the identification, distribution, and toxicological impact of these plants is important for prevention and management. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, toxic mechanisms, and management strategies of toxic plants in relation to equine health.
Geor RJ, Becker RL, Kanara EW, Hovda LR, Sweeney WH, Winter TF, Rorick JK, Ruth GR, Hope E, Murphy MJ.Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.
McConnico RS, Brownie CF.Two horses with red maple (Acer rubrum) toxicity responded to treatment with high doses of vitamin C (ascorbic acid), in addition to blood transfusions, and intravenous fluid therapy. The clinical course included Heinz body anemia, marked methemoglobinemia, depression, and evidence of severe tissue anoxia. Clinical recovery was dramatic with stabilization achieved 36 hours following the initiation of ascorbic acid therapy.
Park DL, Rua SM, Mirocha CJ, Abd-Alla ES, Weng CY.Naturally contaminated corn implicated in an outbreak of equine leukoencephalomalacia (ELEM) in southeastern Arizona was analyzed for mutagenic potential using the Salmonella/microsome mutagenicity assay before and after treatment with the ammonia procedure. Crude acetonitrile: water (1 + 1) extracts of high-pressure/ambient temperature (HP/AT) ammonia decontaminated, HP/AT plus low pressure/high temperature (LP/HT), and non-ammoniated fumonisin contaminated corn were tested for mutagenic potentials. Relatively pure (approx. 90%) fumonisin B1 standard was also tested for comparison purposes. T...
Petroski RJ, Powell RG, Clay K.Stipa robusta (= Stipa vaseyi) is a perennial grass found in certain areas of the southwestern United States. It is commonly known as sleepygrass, as horses that ingest this grass may become profoundly somnolent or stuporous for periods of time lasting up to several days. In an attempt to determine the active principle(s), fractionation of a methanolic extract of sleepygrass infected with an Acremonium endophyte has yielded lysergic acid amide (20 micrograms/g dry wt), isolysergic amide (8), 8-hydroxylsergic acid amide (0.3), ergonovine (7), chanoclavine-I (15), and N-formylloline (18). Relate...
Nation PN.Over sixteen years, 49 horses were diagnosed by Alberta Agriculture Animal Health laboratories as having "alsike clover poisoning". There was a distinct northwestern distribution of cases, the majority coming from the Peace River district. This distribution is opposite to that of the Alberta horse population, but coincides with areas of alsike clover cultivation. Cases could be divided into chronic or nervous clinical presentations, as described by Schofield. Tissues from 45 animals were retrieved and examined microscopically. Significant histological lesions were confined to the liver and con...
Grabner A, Goldberg M.In a blind study serum and cerebrospinal fluid (CSF) of control horses and of horses in hepatic coma after chronic food intoxication with Senecio alpinus were collected simultaneously and the composition of free amino acids was determined. The hepatic encephalopathy index in serum (less than 1.65) and in CSF (less than 1.11) of liver patients was distinctly less than to the control values in serum (greater than 2.42) and in CSF (greater than 1.49). The serum concentrations of glutamic acid in hepatic coma were elevated five-fold in comparison to the controls. An indication of ammonia decontami...
Ross PF, Rice LG, Plattner RD, Osweiler GD, Wilson TM, Owens DL, Nelson HA, Richard JL.Ninety-eight samples of feeds associated with 44 cases of equine leukoencephalomalacia (ELEM) and 83 samples of feed associated with 42 cases of a porcine pulmonary edema syndrome (PPE) were analyzed for fumonisin B1 (FB1). For comparison purposes, 51 feed samples not associated with PPE or ELEM were also analyzed. Feed associated with ELEM contained FB1 ranging from less than 1 microgram/g to 126 micrograms/g with 75% of the cases having at least 1 sample above 10 micrograms/g. Feeds associated with PPE ranged from less than 1 microgram/g to 330 micrograms/g with 71% of the cases having at le...
Pearson EG.Of 41 equids referred to a veterinary teaching hospital in the Pacific northwest because of dyspnea and inspiratory noise, 3 ponies were diagnosed as having liver failure, most likely attributable to pyrrolizidine alkaloid toxicosis. Dyspnea appeared to be caused by laryngeal and/or pharyngeal paralysis. It is proposed that this paralysis was a manifestation of hepatic encephalopathy. Although these clinical signs are not common for pyrrolizidine toxicosis, practitioners should be aware of the possibility so that misdiagnosis of other causes of inspiratory dyspnea may not be made.
Takeda A, Suzuki E, Kamei K, Nakata H.Several kinds of loline-type alkaloids, norloline, loline, N-acetylnorloline, N-acetylloline, N-formylnorloline, N-formylloline and N-methylloline were detected in the urine of race-horses. Furthermore, a new compound of the alkaloids, N-senecioylnorloline, was also found and identified. These compounds were mainly identified by means of gas chromatography-mass spectrometry (GC-MS) and gas chromatography-fourier transform-infrared spectrometry (GC-FT-IR). A certain plant of Gramineae containing four kinds of loline-type alkaloids was found in a bale of hay used for the horse forage. The taxono...
Galey FD, Whiteley HE, Goetz TE, Kuenstler AR, Davis CA, Beasley VR.Twelve light horse geldings developed laminitis within 8 to 12 h of being dosed by nasogastric tube with an aqueous extract of black walnut (Juglans nigra). Four of the 12 horses developed the severe signs of grade 3 laminitis (lame at a walk, refused to lift feet). Laminitis was accompanied by mild depression and limb oedema. There was no evidence of shock or colic. The horses developed neutropenia by 4 h after dosing with the extract, which shifted to a relative neutrophilia by 8 to 12 h. Minimal increases in plasma epinephrine and cortisol concentrations were suggested in severely affected ...
Delbeke FT, Debackere M.A high pressure liquid chromatographic (HPLC) method for measuring the theobromine content in cocoa husks, pelleted food and horse urine is described. Starting with 2 ml of urine, concentrations of 500 ng/ml could easily be detected. When feed containing 38.4 mg of theobromine was given twice daily to horses for 2 1/2 days, two days were needed after the last intake before the theobromine concentrations fell below the threshold value of 2 micrograms/ml. The time at which the peak excretion rate occurred varied from 2 to 12 h after the last administration, while the excretion rate seemed to be ...
Kamphues J, Meyer H.Following feeding of a new delivery of hay (bought in Southern Germany) 3 horses out of a unit of 17 developed colic within a few days one horse died. Post-mortem there was an intensive accumulation of serous or serous-haemorrhagic fluid in the thorax and abdomen. The hay was heavily contaminated by autumn crocus (colchicum autumnale)--about 1.48% of total mass. Other feedstuffs were of good quality and following removal of the affected hay no further cases of colic occurred. The pathological findings also indicated a colchicine intoxication.
Milne EM, Pogson DM, Doxey DL.Poisoning with Senecio jacobaea (ragwort) is a common cause of chronic liver disease in horses in Britain. The major clinical signs are the result of hepatic failure but gastric impaction has recently been associated with the disease. The present paper describes three cases of secondary gastric impaction associated with ragwort poisoning. In each case the impaction was the cause of death or necessitated euthanasia.
Galey FD, Twardock AR, Goetz TE, Schaeffer DJ, Hall JO, Beasley VR.Twelve horses, with acute laminitis (primarily in the forefeet) at 12 hours after intragastric dosing with an aqueous extract of black walnut (Juglans nigra) heart-wood, were studied. The distribution of perfusion of blood to the foot and to outlined regions within the foot was quantified, using gamma scintigraphy of regionally infused 99mTc-labeled macroaggregated albumin, before and 12 hours after extract administration. Horses 1 to 3 were not studied further. Perfusion was quantified again for horses 4 to 12 at 84 hours after extract administration. At the onset of acute laminitis, horses 7...
Beier RC, Norman JO.White snakeroot (Eupatorium rugosum Houtt) has been known to cause trembles in animals and milk sickness in humans since the American Revolution. It still continues to poison animals. Horses and goats are particularly sensitive to white snakeroot poisoning. Resurgence of livestock production on small farm units, and utilization of fresh raw milk may result in milk sickness; if the animals have white snakeroot exposure. The goat is the only animal with good toxicity threshold data. In other animals and humans the toxicity thresholds of white snakeroot are not known, and that until responsible t...
Uhlinger C.Black walnut toxicosis was diagnosed in 10 horses at one stable. The time from exposure to shavings to development of clinical signs was 8 to 12 hours. Most common clinical signs were moderate to severe laminitis (Obel grade 2 or 3), pitting edema of the distal portion of the limbs, and rapid respiratory rate. Two horses had clinical signs of colic and 2 other horses had anorexia and lethargy. All 10 horses recovered without complications.
Nicholson SS.Grasses that are essential components of livestock grazing programs sometimes are the source of tremorgenic toxicants to the animals consuming them. Morbidity can be high but mortality need not be if management closely observes the cattle daily and removes them at first sign of trouble. Specific treatment generally is not available nor needed. Survivors recover completely within a few days or weeks, except in chronic phalaris poisoning, where sheep and cattle may die after prolonged illness--or at least not make an economical recovery. Certain poisonous plants are responsible for tremorgenic s...
Nation PN.Trifolium hybridum (alsike clover) has been implicated as the cause of two diseases of the horse. One of these is photosensitivity, of which alsike clover is only one of a number of presumed causal agents. The other is a fatal syndrome which is known as "alsike clover poisoning" and which is manifest by progressive loss of condition, signs of hepatic failure, and varying degrees of neurological impairment. The underlying lesion of alsike clover poisoning is fibrosis and proliferation of the biliary tree. The experimental evidence implicating alsike clover as the cause of this syndrome comes en...
Cornick JL, Carter GK, Bridges CH.Chronic hepatic disease was diagnosed in 6 horses with history of anorexia and weight loss. These horses consistently had abnormally high serum gamma-glutamyltransferase activities, total and direct bilirubin and blood ammonia values, and sulfobromophthalein clearance times, whereas serum iditol dehydrogenase, aspartate transaminase, and alkaline phosphatase activities were variable. In the 6 horses, histologic examination of the liver revealed lesions of chronic hepatitis with varying degrees of fibrosis. All 6 horses had ingested kleingrass (Panicum coloratum) for variable periods. Three hea...
McDonald GK.A six year old Percheron mare was presented with a history of spontaneous unilateral epistaxis of 24 hours duration. The blood one stage prothrombin and partial thromboplastin times were markedly prolonged. A diagnosis of moldy sweetclover poisoning was made on the basis of the history and clinical and laboratory findings. A single whole blood transfusion and four daily intravenous injections of vitamin K(3) proved to be a successful treatment.
Sazmand A, Yavari M, Babaei M, Nourian A, Otranto D.Migration of Ascaris lumbricoides through the papilla of Vater in humans, and entry into the biliary tree, is well-recognised. Ascaris suum and Toxocara vitulorum have been recovered from the liver of swine and buffalo. We necropsied a Persian Kurdish filly at age 6 months, weighing ∼100 kg. Death evidently was caused by oleander (Nerium oleander) intoxication. An 8-cm adult male Parascaris was found at the lobar-left hepatic bile duct junction. We suggest that the nematode entered anteriorly into the hepatic tree, via the duodenum, major duodenal papilla, bile duct, left hepatic duct and f...
Tennant B, Dill SG, Glickman LT, Mirro EJ, King JM, Polak DM, Smith MC, Kradel DC.From June 1975 through June 1979, acute hemolytic anemia developed in 11 horses from 7 New York farms. Of the 7 horses that died, 6 had methemoglobinemia. In the 4 horses that recovered, methemoglobinemia was not observed. but Heinz body formation was seen in 3 of the 4. On 2 of the premises involved, frank methemoglobinemia was observed concurrently with Heinz body formation, suggesting a relationship between the pathogenesis of methemoglobinemia and Heinz body formation in the hemolytic process. In addition to the 11 cases described, 22 clinically similar cases were reported to us during the...
Munday JS, Finch SC, Vlaming JB, Sutherland BL, Fletcher LR.To investigate whether Mediterranean tall fescue (Lolium arundinaceum (Schreb.) Darbysh. (syn Festuca arundinacea)) infected with selected fungal endophytes (Epichloë coenophiala (formerly Neotyphodium coenophialum)) caused equine fescue oedema when grown in New Zealand, and to examine the pathological changes associated with this intoxication. Methods: Horses were grazed on Mediterranean tall fescue that was infected with the endophytes AR542 (n=2), or AR584 (n=3), or Mediterranean tall fescue that was endophyte-free (n=2). Blood samples were taken up to 7 days after the start of feeding to ...
Wilson SJ, Taylor J, Gibson J, McKenzie R.A dense population of Pimelea trichostachya plants (Family Thymelaeaceae) in pasture poisoned a horse herd in southern inland Queensland in October-November 2005. Plant density was 2 to 45 g wet weight/m(2) (mean 16 g/m(2)) from 5 to 69 plants/m(2) (mean 38 plants/m(2)) representing 3 to 20% (mean 9%) of the volume of pasture on offer. Ten of 35 mares, fillies and geldings were affected. Clinical signs were loss of body weight, profound lethargy, serous nasal discharge, severe watery diarrhoea and subcutaneous oedema of the intermandibular space, chest and ventral midline. Pathological finding...
Barr AC, Reagor JC.Horses poisoned by a plant may show a myriad of clinical signs. Awareness of the poisonous plants growing in a given area and those that are likely to appear in hay and their associated clinical signs can be instrumental in making diagnoses. More importantly, the information can be shared with clients to help prevent plant poisonings in horses.
Divers TJ, George LW, George JW.Signs of acute hemolytic anemia developed in 4 adult horses from 2 Georgia farms 3 to 4 days after the ingestion of wilted leaves from cut red maple trees (Acer rubrum). Clinical findings included weakness, polypnea, tachycardia, depression, icterus, cyanosis, and brownish discoloration of the blood and urine. Blood changes included methemoglobinemia, free plasma hemoglobin, decreased pcv, and Heinz bodies in erythrocytes. These findings plus hemoglobinuria suggested intravascular hemolysis. Three of the 4 horses diet 5 to 7 days after ingestion of the leaves. Gross pathologic changes included...
Delbeke FT, Debackere M.A high pressure liquid chromatographic (HPLC) method for measuring the theobromine content in cocoa husks, pelleted food and horse urine is described. Starting with 2 ml of urine, concentrations of 500 ng/ml could easily be detected. When feed containing 38.4 mg of theobromine was given twice daily to horses for 2 1/2 days, two days were needed after the last intake before the theobromine concentrations fell below the threshold value of 2 micrograms/ml. The time at which the peak excretion rate occurred varied from 2 to 12 h after the last administration, while the excretion rate seemed to be ...
Odriozola ER, Rodríguez AM, Micheloud JF, Cantón GJ, Caffarena RD, Gimeno EJ, Bodega JJ, Gardey P, Iseas FB, Giannitti F.Solanum glaucophyllum, a toxic plant known for its calcinogenic effects, causes enzootic calcinosis in ruminant and monogastric animals. We describe an outbreak of enzootic calcinosis that occurred in a herd of 110 horses grazing pastureland heavily contaminated with S. glaucophyllum in Buenos Aires province, Argentina. Ten horses developed clinical signs, and 6 horses died. Clinical signs included abnormal gait (stiff-legged action, short strides), stiffness, thoracolumbar kyphosis, reluctance to move, wide stance, chronic weight loss, weakness, recumbency, and difficulty standing. Autopsy of...
Gish A, Robveille C, Gicquel T, Allorge D, Gault G, Gaulier JM.Analytical detection of Oenanthe crocata toxins in biological samples is challenging because of their instability, the lack of commercially available standards and the exceptionally low detection of these molecules using mass spectrometry. This work aims to report the used analytical methods that allowed identification of the main plant toxins in biological samples from an equid (an Arabian horse) fatality related to hemlock water dropwort (Oenanthe crocata Linnaeus) intake. Using both LC-DAD and LC-HRMS methods allowed identification (i) of oenanthotoxin in roots found on the site, root fragm...
Huxtable CR, Chapman HM, Main DC, Vass D, Pearse BH, Hilbert BJ.A severe paretic syndrome accompanied by intense neuronal lipofuscinosis is described in sheep and horses exposed to Trachyandra divaricata. This is a newly recognised toxic hazard for grazing livestock in the coastal region of the south west of Western Australia. Animals appear to become affected over a period of weeks when summer conditions induce a scarcity of alternative feed. The disease is discussed in relation to its recent documentation in South Africa where the plant is indigenous.
Knight HD, Costner GC.During the summer and fall of 1973, a few horses, goats, and cattle in the Napa Valley of California became intoxicated by bromide via the ingestion of volunteer oat hay that had been cut from a field treated with methyl bromide, a soil fumigant. The bromide content of the hay ranged from 6,00 to 8,400 ppm. Signs of intoxication were lethargy, weakness, and ataxia. Animals experimentally fed the contaminated hay developed signs of intoxication between the 7th and 9th days.
Rohner Mächler M, Glaus TM, Reusch CE.In a Bearded Collie with acute weakness, hematemesis, melena, painful abdomen and pale mucous membranes a hematocrit of 13% and panhypoproteinemia were found. This combination of findings was the manifestation of severe gastrointestinal bleeding. Despite intensive laboratory and imaging investigations no systemic or local cause could be identified. After repeated client interrogation it was found that the dog had been receiving a food supplement for equines. It was further detected that this supplement besides a shell extract also contained willow (Salicaceae) and meadowsweet (Filipendula, Spi...
Haughan JE, Missanelli JR, You Y, Stefanovski D, Soma LR, Robinson MA.Glaucine, an aporphine alkaloid with anti-tussive, anti-inflammatory, and anti-nociceptive properties, has been identified in post-race samples from racehorses. To investigate pharmacokinetics of glaucine in horses, a three-way crossover study of intravenous and oral glaucine (0.1 mg/kg) and orally administered tulip poplar shavings (50 g shavings = 0.001 mg/kg glaucine) was performed in six horses. A two-compartment model best described IV administration with alpha ( ) and beta ( ) half-life lives of 0.3 (0.1-0.7) and 3.1 (2.4-7.8) h, respectively. The area under the curve ( ) was ...
Brewer K, Dirikolu L, Hughes CG, Tobin T.Scopolamine (L-hyoscine) identifications, often in small-number clusters, have been reported worldwide in performance horses over the last 30 years. Scopolamine is an Association of Racing Commissioners International (ARCI) class 3, penalty class B, substance with potential to affect performance. As such, scopolamine identification(s) in race or performance horses can result in significant penalties for the connections of the horse(s). Reviewed here is the worldwide distribution of scopolamine containing plants (primarily Datura spp.), with estimates of their potential toxicity to horses throu...
Keeler RF, Balls LD, Shupe JL, Crowe MW.Cows, ewes, and mares varied considerably in susceptibility to toxicoses from the oral administration of the piperidine alkaloid, coniine. Cows were most susceptible and ewes least. Only calves had teratogenic effects from maternal administration of coniine during gestation; lambs and foals were apparently resistant. Results suggest that the marked differences between cattle and sheep are probably not due to variation in gut absorption or rumen metabolism.
O'Sullivan BM, Goodwin JA.On 6 properties in south-western Queensland an outbreak of nervous disease occurred horses due to ingestion of Swainsonia (Darling pea). Loss of condition, depression, hyperaesthesia and hyperexcitability were seen in affected horses. At autopsy of 2 horses generalised c ytoplasmic vacuolation was seen in the neurones of the central nervous system and in the liver, adrenal and thyroid. The clinical and pathological features were similar to those described in horses suffering from Swainsona poisoning in Australia and Astragalus and Oxytropis in North America.
Rohrbach BW, Green EM, Oliver JW, Schneider JF.Loline and ergot alkaloids found in endophyte-infected (Acremonium coenophialum) tall fescue (EITF) cause vasoconstriction of equine vessels in vitro. An aggregate risk study was used to evaluate the association between horses exposed to EITF and development of laminitis. Veterinary teaching hospitals participating in the Veterinary Medical Data Base were grouped by whether equine accessions were likely to have been at high, moderate, or low risk for exposure to EITF. From 1980-1990, there were 185,781 accessions, of which 5,536 had diagnosis of laminitis. Proportion of equine accessions with ...
McGorum BC, Anderson RA.To test the hypothesis that equine grass sickness may be associated with the ingestion of cyanogenic glycosides from white clover (Trifolium repens), the concentrations of whole blood cyanide, and plasma and urinary thiocyanate, the main metabolite of cyanide, were measured in 12 horses with acute grass sickness and 10 horses with subacute grass sickness, and in 43 control horses, of which 21 were co-grazing with cases of acute grass sickness, 12 grazed pastures where grass sickness had not been reported, and 10 were stabled horses. The healthy horses which grazed with cases of acute grass sic...
Winter JC, Thieme K, Eule JC, Saliu EM, Kershaw O, Gehlen H.Primary photosensitization rarely occurs in horses and can easily be misinterpreted. Descriptions of the disease in horses after ingestion of parsnip are lacking. The aim of this case series was to describe the dermatological and ocular changes due to photosensitization and to raise awareness of parsnip being a possible aetiologic agent. Methods: Nine horses from three different stables in Berlin and Brandenburg, Germany, presented variable degrees of erythema, scaling, crusting and necrosis of unpigmented skin at the head and prepuce. Horses were of different breeds with a median age of 15 ...
Naudé TW, Gerber R, Smith RJ, Botha CJ.Datura poisoning of horses is extensively reviewed. An outbreak of intractable impaction colic affecting 18 of 83 horses was stopped by withdrawing dried tef hay contaminated with young Datura plants. The dried, botanically identified Datura stramonium and D. ferox contained respectively 0.15% mass/mass (m/m) hyoscyamine as well as 0.16% m/m hyoscine (scopolamine) and only hyoscine at a concentration of 0.11% m/m. Immature, unidentifiable plants resembling D. stramonium, contained 0.14% m/m and 0.12% m/m of the 2 respective tropane alkaloids. The outbreak was characterised by protracted and re...
Bauquier J, Stent A, Gibney J, Jerrett I, White J, Tennent-Brown B, Pearce A, Pitt J.Investigation of toxicosis caused by Malva parviflora was required after 4 horses from the same farm developed severe muscle fasciculations, tachycardia, sweating and periods of recumbency leading to death or euthanasia after ingesting the plant. Objective: To describe historical, clinical, clinicopathological and pathological findings of 4 horses with suspected M. parviflora toxicosis. The role of cyclopropene fatty acids (found in M. parviflora) and mechanism for toxicosis are proposed. Methods: Case series. Methods: Historical, physical examination, clinicopathological and pathological find...
Le Bars J, Le Bars P.Successful investigation and prevention of mycotoxic problems requires close collaboration between scientists from several disciplines ranging from agronomists and technologists required during production of food and feeds, to toxicologists and pathologists examining the effects of mycotoxins on animals and man. Zootoxic metabolites following fungal infection result from four general mechanisms: (i) secondary fungal metabolism (mycotoxins, eg, aflatoxins); (ii) bioconversion of vegetal compounds (eg, dicoumarol); (iii) plant reactions (phytoalexins, eg, coumestrol); and (iv) plant-fungus assoc...
Machado M, Camacho AL, Coubrough C, R R Queiroz-Machado C, Custodio C, Barros CSL, Riet-Correa F, Menchaca A.We reported thirteen cases of bilateral stringhalt associated with Hypochaeris radicata that occurred in horses in Uruguay during a severe drought in the summer of 2023. All horses were affected chronically and progressively by bilateral hyperflexion of hindlimbs. In two severely affected horses, the main histological lesions included neuronal chromatolysis and axonal spheroids in the ventral gray horn in the lumbar and sacral spinal cord and axonal degeneration and digestion chambers in ventral roots fibers and long peripheral nerves. We suggest that in addition to injuries to peripheral nerv...
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...