Diagnostic guidelines for ruminant toxicoses.

Management of poisoning is best accomplished when an accurate diagnosis is made and enhanced by attention to five major diagnostic criteria: history, clinical signs, clinical laboratory evaluation, lesions, and chemical analysis. Used properly, all of these factors allow for a better understanding of clinical poisoning. Although not all of these are possible for individual incidents, a systematic approach to support these criteria will bring a more useful assessment of risk and an accurate diagnosis.

Evaluation of XPC and prototypes on aflatoxin-challenged broilers.

Various products and prototypes were added to poultry diets during an aflatoxin challenge on growth and histological parameters. Male broiler chicks were randomly assigned to 8 treatment groups with 8 replicates/treatment and 3 birds/replicate. Treatments were as follows: 1) negative control containing no aflatoxin (NC); 2) positive control containing aflatoxin (PC); 3) 0.

Fumonisin B-glucose reaction products are less toxic when fed to swine.

The effects of fumonisin B-glucose reaction products in swine diets was examined. Pigs were fed diets containing 528 micromol of total fumonisin B/kg (FB), 528 micromol of total FB-glucose adducts/kg (FB-G, 122 micromol of unreacted FB/kg), or 0 micromol of total FB/kg for 15 days to test the efficacy of the FB-G reaction products in detoxifying FB. Weight gain in FB pigs was lower than in FB-G or controls, which was correlated with feed intake reduction in FB pigs.

Glucose reaction with fumonisin B1 partially reduces its toxicity in swine.

Acute and subacute intraperitoneal doses of fumonisin B(1) (FB(1)) were administered to test the efficacy of the FB(1)-glucose reaction products in detoxifying FB(1) in swine. In the acute study at 11 mumol of FB(1)/kg of body weight, five of six pigs administered FB(1) and four of six pigs administered FB(1)-glucose died from acute pulmonary edema. Analysis of weight gain, serum aspartate aminotransferase and gamma-glutamyltransferase, total cholesterol, and pathological evaluation did not provide evidence of protection against FB(1) toxicity by the FB(1)-glucose reaction products.

Overingestion of methionine tablets by a dog.

Methionine tablets are used as urinary acidifiers for pets and to decrease damage from dog urine to lawns. A 39-kg Labrador Retriever ingested approximately 350 tablets containing 150 mg methionine/tablet and was presented after repeated episodes of vomiting. The only abnormality was posterior ataxia suggestive of spinal cord injury.

Characterization of fumonisin B(1)-glucose reaction kinetics and products.

The reaction of fumonisin B(1) with the reducing sugar D-glucose can block the primary amine group of fumonisin B(1) and may detoxify this mycotoxin. A method to separate hundred milligram quantities of fumonisin B(1)-glucose reaction products from the excess D-glucose with a reversed-phase C(18) cartridge was developed. Mass spectrometry revealed that there were four primary products in this chain reaction when fumonisin B(1) was heated with D-glucose at 65 degrees C for 48 h: N-methyl-fumonisin B(1), N-carboxymethyl-fumonisin B(1), N-(3-hydroxyacetonyl)-fumonisin B(1), and N-(2-hydroxy, 2-carboxyethyl)-fumonisin B(1).

Diagnostic analyses of biological agent-caused syndromes: laboratory and technical assistance.

The impact of a bioterrorism attack can be greatly reduced by collaboration among primary healthcare providers, laboratories, the veterinary community, public health officials, and emergency response personnel. Improved communication and coordination are essential to make this happen. As a first-line provider, the emergency physician must keep in mind the possibility of bioterrorism and alert the laboratory so that samples can be processed in the correct fashion.

Mycotoxins.

Horses consume feed grains and forages that can produce a range of mycotoxins resulting from mold invasion. Toxicosis of horses often occurs from fumonisins or aflatoxin in grains, from the tremorgenic mycotoxins in dallis grass, or from slaframine in red clover. Fumonisin toxicosis often is severe and fatal, and aflatoxin can be acute or chronic and debilitating.

Mycotoxins. Contemporary issues of food animal health and productivity.

Modern agriculture and production animal medicine require attention to high-quality feeds that are free from mycotoxin contamination that can cause economically important decreases in productivity. Maintaining current information about effects of mycotoxins on feed intake and growth, reproductive efficiency, and possible immunosuppression aid in effective consultation with livestock producers. Investigation and determination of potential production losses related to mycotoxins should use historical, clinical, laboratory, and experimental information to objectively evaluate whether mycotoxin contamination is clinically relevant.

Effects of fumonisin-contaminated corn screenings on growth and health of feeder calves.

Fumonisins are myocotoxins produced by Fusarium moniliforme and F. proliferatum, common molds of corn in North America. The toxin is at especially high concentrations in corn screenings.

Experimental equine leukoencephalomalacia, toxic hepatosis, and encephalopathy caused by corn naturally contaminated with fumonisins.

A study to evaluate the effects of dietary fumonisin B1 was conducted using 6 ponies (4 test and 2 control). A ration naturally contaminated with fumonisin B1 was fed in 3 phases: 1) 44 ppm fumonisin B1, 2) less than 1 ppm fumonisin B1, and 3) 88 ppm fumonisin B1. All ponies were monitored daily, weighed weekly, and limit fed at a rate of 0.

Arsenic concentrations in tissues and body fluids of dogs on chronic low-level dietary sodium arsenite.

Twenty-four female Beagle dogs, 7-8 months old, were assigned to 4 groups. Control, low-dosage, medium-dosage, and high-dosage groups were offered 0, 1, 2, and 4 mg of sodium arsenite per kilogram of body weight per day (mg/kg/day), respectively, in their feed (equivalent to 0.0, 33.

A review and update of animal toxicoses associated with fumonisin-contaminated feeds and production of fumonisins by Fusarium isolates.

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.

Characterization of an epizootic of pulmonary edema in swine associated with fumonisin in corn screenings.

In 1989, corn screenings were associated with acute interstitial pulmonary edema, hydrothorax, and death in swine. Attack rate was 5-50%, case fatality rate was 50-90%, and clinical course was 1-2 days. Screenings from farms with pigs affected with pulmonary edema contained 20-330 micrograms fumonisin B1 per gram.

Fumonisin B1 concentrations in feeds from 45 confirmed equine leukoencephalomalacia cases.

During the fall of 1989 and winter of 1990, numerous reports of equine leukoencephalomalacia (ELEM) occurred from many regions of the United States. Typically, horses were consuming feed partially or entirely composed of corn and/or corn screenings. From October 1989 through May 1990, samples from 55 confirmed or suspected ELEM cases were received at the National Veterinary Services Laboratories, Ames, Iowa, for fumonisin B1 analysis.

Concentrations of fumonisin B1 in feeds associated with animal health problems.

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.

Production of fumonisins by Fusarium moniliforme and Fusarium proliferatum isolates associated with equine leukoencephalomalacia and a pulmonary edema syndrome in swine.

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.

Cocklebur toxicosis in cattle associated with the consumption of mature Xanthium strumarium.

Cockleburs (Xanthium spp.) are herbaceous annuals with worldwide distribution. Toxicoses are usually associated with the consumption of the seedlings in the cotyledon stage, which contain a high concentration of the toxic principle, carboxyatractyloside.

Formate metabolism in young swine.

Formate generated from methanol metabolism in vivo is the chemical entity responsible for the development of the methanol toxicity syndrome in the monkey. Compared to rats, monkeys are in a state of folate deficiency. This leads to a decreased ability to dispose of formate generated leading to its accumulation and the subsequent development of the classic symptoms of methanol toxicity.

Fumonisin B1 levels associated with an epizootic of equine leukoencephalomalacia.

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.

In vitro effects of cyclopiazonic acid mycotoxin on turkey papillary muscles.

An in vitro bioassay system was used to study the effects of cyclopiazonic acid (CPA) mycotoxin on cardiac muscle. Acute exposure to 6 micrograms of CPA/ml of modified Krebs-Henseleit solution significantly (P less than 0.05) decreased 5 in vitro turkey cardiac muscle performance criteria: maximal weight a muscle could lift; maximal contraction velocity; relaxation velocity; time to peak contraction; and total time for muscle contraction and relaxation.

Technical workshop report: Working Group II: agricultural occupational health and safety services for farmers and ranchers.

This work group felt that there is compelling evidence that effective occupational health services are essential to improve the serious occupational safety and health problems in agriculture. Program initiatives may be stimulated by federal and state governments, but development and implementation must involve the grassroots farm community and local resources. Other countries (Sweden, Finland, Canada) are far ahead of the United States in this area and serve as examples.