Fumonisin toxicosis in swine: clinical and pathologic findings.

From a series of experimental studies with pigs (12-16 kg), either pulmonary edema or liver failure emerged as a distinct pathogenetic expression of fumonisin B1 (FB1) toxicosis. The primary determinant as to which pathogenetic consequence developed was the quantity (dose) of the mycotoxin fed or intubated per kilogram of body weight per day. Pigs intubated with a minimum of 16 mg FB1/kg/day developed severe interlobular edema with or without hydrothorax and variably severe pulmonary edema. Pigs intubated with < 16 mg FB1/kg/day or pigs fed diets containing 200 mg FB1/kg of feed developed marked icterus and hepatocellular necrosis. The spectrum of degrees of severity of pulmonary edema observed in the experimental pigs allowed rational speculation regarding evolution of the pathologic changes.

Pulmonary edema and hydrothorax in swine produced by fumonisin B1, a toxic metabolite of Fusarium moniliforme.

Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings. These postmortem observations were reproduced in younger swine (16-24 kg) that died within 1 week when fed the corn screenings under experimental conditions. Additionally, pulmonary edema and hydrothorax occurred in a pig (7.1 kg) that died after receiving 4 daily intravenous injections of fumonisin B1. A fungus was isolated from the corn screenings that is identical to Fusarium moniliforme MRC-826 in colony morphology and under microscopic examination.

Acute, fatal illness in cattle exposed to boron fertilizer.

Twenty-six cows died after accidental exposure to boron fertilizer. Cows developed diarrhea, weakness, ataxia, signs of depression, and died, usually within a few hours. Seizure-like behavior was noticed in 2 cows, and 2 were suspected of aborting. High boron concentrations in tissues from affected cows confirmed ingestion of an appreciable amount of boron fertilizer. In an attempt to confirm the diagnosis of boron poisoning, boron fertilizer was administered to goats. A kid goat given 3.6 g of fertilizer/kg of body weight developed clinical signs similar to those seen in the cattle. Boron compounds such as sodium borate and boric acid have been considered generally nontoxic, and reports of livestock toxicosis are uncommon. This case report suggests that these compounds may be palatable under certain circumstances leading to ingestion of toxic quantities.

Aflatoxicosis in cattle pastured in a field of sweet corn.

Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet corn. Necropsy of 1 cow that died revealed anasarca and a pale tan liver. In this cow, microscopic examination revealed edema of all soft tissues and liver lesions consistent with aflatoxicosis. Samples of corn taken from the field contained 2,365 ng of aflatoxin/g of corn. Weather conditions were conducive to the formation of aflatoxins by Aspergillus flavus and A parasiticus.

Aflatoxicosis in feeder cattle.

Aflatoxicosis was diagnosed as the cause of deaths in a group of crossbred feeder steers. Corn used in the ration being fed the steers was found to be contaminated with 1,500 ng of aflatoxin/g. Residues of the mycotoxin were detected in kidney tissue, and microscopic examination of liver sections revealed lesions typical of aflatoxicosis.

Cassia occidentalis toxicosis in growing pigs.

Approximately 70 feeder pigs developed ataxia and other signs of neuromuscular dysfunction. The ration fed the pigs was found to be contaminated with Cassia occidentalis seeds. Experimentally, other feeder pigs were fed this ration, and they developed ataxia and other signs of neuromuscular dysfunction within 6 to 8 weeks. In further experiments, feeder pigs fed diets containing 1%, 2%, or 4% ground cassia seeds also became intoxicated. Microscopically, diaphragmatic myopathy and pancreatic tissue necrosis were the principal pathologic findings.

Fumonisin-induced pulmonary edema and hydrothorax in swine.

Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings. These postmortem observations were reproduced in younger pigs that died within 1 week when fed the corn screenings under experimental conditions. Additionally, pulmonary edema and hydrothorax were induced in a pig that died after receiving 4 daily intravenous injections of fumonisin B1, a toxic metabolite produced by Fusarium moniliforme.

Gas-liquid chromatographic determination of strychnine in grain baits.

A simple and rapid gas-liquid chromatographic procedure, using a 6' times 1/4'' glass column packed with 5% SE-30 on Chromosorb W (DMCS) and a flame ionization detector, is described. Grain baits containing strychnine alkaloid are ground, mixed, and extracted by shaking with chloroform containing an internal standard, 1,3,5-triphenylbenzene. Without further cleanup, extract filtrates are injected directly into a gas chromatograph. Peak height ratios are used for quantitation of strychnine. The analysis of commercial samples shows that the method compares well with a commonly employed ultraviolet spectrophotometric method; good precision, with recoveries ranging from 89.9 to 91.7%, is obtained in the analysis of prepared samples. The method is sensitive to 2 mug strychnine.

High-performance liquid chromatographic determination of strychnine in grain baits.l.

A simple and rapid high-performance liquid chromatographic procedure is described for the determination of strychnine. Grain baits containing strychnine alkaloid are ground, mixed, and extracted by shaking with chloroform. Without further cleanup, extract filtrates are injected directly into a liquid chromatograph. Chromatography is complete within 7 min and peak heights are used for quantitation. Separations were made on a 30 cm times 4 mm id stainless steel column packed with mu Porasil (8-12 mum silica). The eluting solvent was methanol-chloroform (10+90) at a flow rate of 2.0 ml/min. Recovery of spiked samples ranged from 91.5 to 95.2%. Confirmation of strychnine from a commercial sample was made by high resolution mass spectrometry with mass agreement to 1.2 ppm.

Separation of rotenoids and the determination of rotenone in pesticide formulations by high-performance liquid chromatography.

The rotenoids deguelin, B-dihydrorotenone, dehydrorotenone, rotenone, 6alpha beta, 12alpha beta-rotenolone, and tephrosin were chromatographed on 8-12 mum silica. A mobile phase of chloroform-isooctane (35+65) pumped at a flow rate of 1 ml/min through a 30 cm column was used and the absorbance of the eluate was monitored at 294 nm. Rotenone, B-dihydrorotenone, deguelin, and dehydrorotenone are completely resolved while 6alpha beta, 12alpha beta-rotenolone and tephrosin chromatograph as one peak. This method has potential as a preparative separation technique for rotenoids. Also described is a procedure to quantitatively measure rotenone in pesticide formulations. Samples were extracted with chloroform and chromatographed at a flow of 2.5 ml/min. The method is rapid (rotenone is eluted in 12 min) and reproducible.

High pressure liquid chromatographic determination of sulfanitran and dinsed in medicated feeds and premixes.

A simple reverse phase high pressure liquid chromatographic method is described for determining sulfanitran (acetyl-p-nitrophenylsulfanilamide) and Dinsed (dinitrodiphenylsulfonylethylenediamine) in a variety of feed premixes and formulations. Feed premixes are extracted with dimethylformamide, and formulated feeds are extracted with hot methanol. The extract is filtered through medium porosity paper and injected into a liquid chromatograph equipped with a 254 nm ultraviolet detector and a 30 cm column packed with muBondapak C18. The mobile phase is acetonitrile-water (45 + 55) at a flow rate of 1.0 ml/min. Chromatography was complete in 10 min and peak heights were used for quantitation. Comparison of analyses of commercial samples by this method and by the AOAC colorimetric method, 42.176-42.179, showed close agreement. Recovery of spiked feed samples ranged from 98 to 105%. Butynorate and roxarsone, 2 other drugs which are normally found in combination with sulfanitran and Dinsed, do not interfere.

Experimental acute inorganic boron toxicosis in the goat: effects on serum chemistry and CSF biogenic amines.

Following acute accidental death of 26 cows exposed to boron fertilizer, effects of inorganic boron treatment in goats were studied. Goats were orally dosed with toxic but sublethal amounts of the fertilizer. Multiple hematologic and serum chemistry parameters were assessed, as were cerebrospinal fluid (CSF) neurotransmitters and some of their metabolites. Significant increases in packed cell volume, hemoglobin, inorganic phosphate, creatine phosphokinase, conjugated bilirubin, sodium, glucose, cholesterol, and aspartate transaminase were recorded. The following serum components were significantly decreased after boron dosing: alkaline phosphatase, magnesium, glutamyltransferase and potassium. There was evidence of a stimulatory effect on both serotonergic and dopaminergic neurons as reflected in elevated CSF monoamine metabolites. Aberrations in clinical behavior, including seizure-like activity, also suggested a central nervous system effect of inorganic boron.

High pressure liquid chromatographic determination of ethopabate in feeds.

A high pressure liquid chromatographic (HPLC) method is described for determining ethopabate in poultry feeds. Feed samples containing ethopabate are finely ground, extracted 30 min by sonification with methanol-water (80 + 20), and filtered. The extract is cleaned up on an alumina column, and the first 4 ml eluate collected is analyzed. The drug is eluted through a muBondapak C18 column with acetonitrile-water (30 + 70) at a flow rate of 1.4 ml/min and detected by ultraviolet absorption at 280 nm. Chromatography is complete in 7 min, and detector response is linear. The drug is quantitated by peak height ratios. The procedure described is reproducible and shows good agreement with the official AOAC colorimetric method. The lower limit of detection is 2 ng by HPLC, making the method applicable to residue analyses.

Canine aflatoxicosis: a continuing problem.

Aflatoxins are hepatotoxic in many species including dogs. In two separate outbreaks, the primary signalment was high morbidity and mortality in hunting dogs presenting with clinical signs of icterus, anorexia and listlessness. Preliminary laboratory examinations revealed toxic hepatitis, bilirubinuria and anemia. In the first case, a feed sample was not available and the diagnosis was established by confirming the presence of significant levels of aflatoxin B1 in tissues. In the second case, cornmeal utilized in formulating the ration contained 511 ng aflatoxin B1 and B2/g. These cases illustrate that aflatoxicosis is a continuing problem despite widespread awareness and testing for aflatoxin.

Effect of a high affinity aluminosilicate sorbent on prevention of aflatoxicosis in growing pigs.

Adding 0.5% hydrated sodium calcium aluminosilicate to diets formulated with aflatoxin-contaminated corn significantly reduced the detrimental effects of the mycotoxin on live weight gains and feed intake. Hepatocellular changes normally associated with aflatoxin consumption could not be detected histopathologically in liver sections from pigs fed contaminated diets plus the aluminosilicate sorbent.

Paralysis in swine due to focal symmetrical poliomalacia: possible selenium toxicosis.

A paralytic disease in swine was observed on three farms located in the same geographical area of Georgia. Postmortem examinations revealed the paralysis to be related to spinal poliomalacia. Feed collected from two of the affected farms was used in a feeding study, and the paralytic condition was reproduced. In pigs from both the feeding trial and field cases, the poliomyelomalacia was characterized by focal, symmetrical lesions located in the cervical and lumbar intumescences. Selenium was detected in the feed at levels ranging from 19 to 24 ppm.

Distribution of aflatoxins in tissues of growing pigs fed an aflatoxin-contaminated diet amended with a high affinity aluminosilicate sorbent.

The effect of hydrated sodium calcium aluminosilicate (HSCAS) added to the diet of swine fed an aflatoxin-contaminated diet on tissue aflatoxin levels was investigated. Pigs were fed control (less than 10 ng/g B1 + B2), contaminated (500-600 ng/g B1 + B2), and contaminated +0.5% HSCAS diets. Tissues analyzed for the presence of aflatoxin B1, B2, and M1 residues included liver, muscle, kidney, and adipose. Addition of HSCAS to the contaminated diet significantly reduced the amount of M1 in liver, kidney, and muscle tissue. Aflatoxin B1 was not reduced in liver or kidney, but was decreased in muscle.