Equine leukoencephalomalacia associated with ingestion of corn contaminated with fumonisin B1

Abstract

This article describes clinical, etiologic and pathologic diagnosis of an outbreak of equine leukoencephalomalacia. Two samples of the corn consumed by the affected horses contained fumonisin B 1 at levels of 46 and 53 µg/g and Fusarium moniliforme, a good in vitro mycotoxin producer.Key words: corn, leukoencephalomalacia, fumonisin, Fusarium moniliforme, chromatographyFumonisins are a group of toxic metabolites produced by Fusarium spp. and Alternaria spp. fungi, especially Fusarium moniliforme (2,10,15), a species well adapted to tropical climates (8,17). These mycotoxins have been detected in oats and corn-based food, even after pelletization (5,19). Among the several types of fumonisin known, fumonisin B 1 (FB 1 ), B 2 (FB 2 ), and B 3 (FB 3 ) have been isolated from naturally contaminated foods and feeds. FB 1 , the most toxic of these compounds (13), is produced in large amounts and is responsible for various toxicoses in domestic animals, including equine leukoencephalomalacia (ELEM) (12,13), pulmonary edema and hydrothorax in pigs (6), diarrhea and reduced body weight in broiler chicks (8) and carcinogenity in rats (15). FB 1 , FB 2 and FB 3 are generally found in feed at a ratio of 8:2:1 (18).The clinical course of ELEM is directly related to the amount of toxin ingested and may be influenced by individual tolerance. Clinical disease may be observed from a few hours to several days after consumption of contaminated rations, but a correct diagnosis is normally possible after an average period of 72 hours. Feed containing more than 10 µg/g of FB 1 is considered toxic and of high risk if administered to animals. Previous studies of ELEM outbreaks have shown that feed contaminated with 1 to 126 µg/g of FB 1 produces clinical signs of the disease in horses (12,19). The aim of this short communication was to describe an outbreak of ELEM in horses and correlate the disease with the presence of both Fusarium moniliforme and FB 1 in corn ingested by the affected animals.The episode occurred in a farm located in southern Brazil, during the spring of 1996, when 3 250 C. A. Mallmann et al. to 4 years old thoroughbred horses (3 males and 1 female; approximate body weight: 400 Kg) were affected. The animals were being fed native grass supplemented with 2 kg of corn/horse/day. Three horses presented clinical signs of ELEM seven days after ingestion of contaminated ration and the forth horse showed similar signs three days later. All horses died within 18 to 30 hours from the start of clinical disease and were necropsied immediately after death. Brain tissue was macroscopically examined and selected areas were sampled for routine histopathology.Two samples of corn fed to the affected horses were analysed for the presence of FB 1 . All the procedures used for extraction, purification, and quantification of FB 1 by high-performance liquid chromatography (HPLC) (GBC Scientific Equipment Pty Ltd. -Victoria, Australia) were adapted from previous studies (3,12). 10 g of ground corn were mixed with 50 ml acetonitri...

Mycotoxin research in Brazil: the last decade in review

“…The clinical, etiologic and pathological diagnosis of an outbreak of equine leukoencephalomacia in Rio Grande do Sul was also described (56). Two samples of corn consumed by the affected horses contained FB 1 (46 and 53 µg/g) and F. moniliforme.…”

Determination of fungal microbiota and mycotoxins in brewers grain used in dairy cattle feeding in the State of Bahia, Brazil

“…Evidence shows the participation of these toxic agents in the etiology of serious pathological processes in production animals associated with animal feeds, including barley, and this kind of contamination has been the subject of intensive scientiWc investigation both in Brazil and in diVerent parts of the world (Kim, Kang, Lee, Lee, & Yoshizawa, 1993;Mallmann, Santurio, & Dilkin, 1999). AXatoxins and ochratoxins are among the various mycotoxins identiWed that play an important role in animal health.…”

Fumonisins in brewers grain (barley) used as dairy cattle feed in the State of Bahia, Brazil

“…These toxins have been related to diVerent toxic eVects in animals, such as leukoencephalomalacia in horses (Mallmann, Santurio, & Dilkin, 1999), pulmonary edema in pigs (Casteel, Turk, & Rottinghaus, 1994), renal and hepatic alterations in cattle (Mathur et al, 2001), and neoplasms in rats (Gelderblom et al, 2001). In humans, the consumption of corn products contaminated with fumonisins have been epidemiological related to the development of esophageal cancer (Chu & Li, 1994;Franceschi, Bidoli, Baron, & La Vacchia, 1995).…”