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COMMON TOXICITIES IN BEEF CATTLE

COMMON TOXICITIES IN BEEF CATTLE. Cynthia Gaskill DVM PhD Veterinary Clinical Toxicology University of Kentucky Veterinary Diagnostic Laboratory. Veterinary Toxicology. Types of toxicants: Plants Bacterial and fungal toxins Venomous animals Pesticides

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COMMON TOXICITIES IN BEEF CATTLE

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  1. COMMON TOXICITIES IN BEEF CATTLE Cynthia Gaskill DVM PhD Veterinary Clinical Toxicology University of Kentucky Veterinary Diagnostic Laboratory

  2. Veterinary Toxicology • Types of toxicants: • Plants • Bacterial and fungal toxins • Venomous animals • Pesticides • Drugs, feed additives, supplements • Industrial, mining chemicals • Dosage absorbed determines if poisoning will occur • HUGE species difference

  3. Veterinary Toxicology • THERE IS NO ONE SINGLE ANALYSIS THAT TESTS FOR ALL TOXINS! • We need to know what we are looking for to order to chose: • The best instrumentation and method • The best sample prep, extraction techniques • The limits of detection/quantification necessary

  4. Causes of Cattle Poisoning • Most common causes of poisoning in cattle diagnosed at UK VDL in last 3 years: • Nitrate intoxication (feed, fertilizer) • Metal poisoning (arsenic, lead, other) • Selenium poisoning • Taxus (yew) poisoning • Botulism • Sulfur intoxication • Pesticide poisoning

  5. Other Causes of Poisoning • Slaframine (legumes) • Gossypol (cottonseeds) • Ionophores (monensin most common) • Miscellaneous byproduct feeds • Various plants suspected (teratogens) • Various mycotoxins found in feeds: • Aflatoxin, vomitoxin, zearalenone, others • Varies by year, environmental conditions, storage conditions

  6. Diagnosis • Many cases of poisoning can be diagnosed using combination of: • History • Clinical examination findings • Basic diagnostic tests • Post-mortem evaluation, histopathology • Specific testing can be used for confirmation • Veterinary input essential!

  7. Case: Heifers • 3 heifers dead in 3 weeks (from a herd of 32 head) • Weak, no energy, unable to get up • Several dead deer found in same area

  8. Case: Heifers • One heifer brought to UKVDL for post-mortem • Marked autolysis but no obvious gross or microscopic findings • Other diagnostic tests normal or negative • Differential diagnoses: • Too many to list here

  9. Case: Heifers • History: • Cattle on 350 acres; moved to this pasture 4 wks ago • Grass pasture, mineral mix provided • No exposures to anything known • Burn pile in pasture • Burned pile about 3 weeks ago • Cattle had access to burn pile • Dead deer found near burn pile

  10. Case: Heifers • Burn pile: • Brush, limbs • Unknown items from previous years, • Remnants of pressure treated lumber

  11. Case: Heifers • Suspected Toxin: • Arsenic – Elemental Analysis Required • Toxicologist’s Needs? • Toxin ID? • Toxin ID and Semi-Quantitation? • Toxin ID and Exact Quantitation? • Specimen for Analysis? • Brain, Liver, Kidney, Digestive Tract Contents • Body Fluids (Urine, Serum, Ocular Fluid) • Suspicious Bait or Bait Containers • Feed

  12. Toxicology Tools Microscopy Ultraviolet / Visible Spectroscopy • Endpoint Reactions • Kinetic Assays Liquid Chromatography • Mass Spectrometry • Fluorescence • UV/Vis Absorbance Complexometric Reactions • Litmus Paper • “Dipstick” Tests Ion Exchange Chromatography Inductively Coupled Plasma • Mass Spectrometry • Atomic Emission Gas Chromatography • Mass Spectrometry • Flame Ionization Detection • Electrochemical Detection

  13. Toxicology Tools X X Microscopy Ultraviolet / Visible Spectroscopy • Endpoint Reactions • Kinetic Assays X Liquid Chromatography X • Mass Spectrometry • Fluorescence • UV/Vis Absorbance Complexometric Reactions • Litmus Paper • “Dipstick” Tests X Ion Exchange Chromatography Inductively Coupled Plasma • Mass Spectrometry • Atomic Emission X Gas Chromatography • Mass Spectrometry • Flame Ionization Detection • Electrochemical Detection

  14. ICP-MS $$$$ Expensive to Purchase ($200,000+) Expensive to Operate (~$15,500/yr) Expensive to Maintain (Labor Costs) Requires Skilled, Dedicated Operator

  15. Case: Heifers • ICP-MS analysis of liver and kidney: • Very high concentrations of arsenic • 15 ppm (liver) and 10 ppm (kidney) on a wet weight basis (normal: <0.2 ppm) • Diagnosis: Arsenic poisoning

  16. Case: Arsenic Poisoning • Sources of arsenic: • Old pressure treated (CCA) lumber • Arsenic concentrated in ashes; available • Old pesticides • Some older drugs • Drilling muds • Feed additives • Contaminated soils • Mining activity

  17. Case: Arsenic Poisoning • Issues that need to be addressed: • Proper disposal of carcasses • Tissue residues/withholding times • Test rest of potentially exposed cattle • Prevent contamination of human food supply • Information to the state vet • Treatment of clinical cases • Cleanup of environment • Deer: exposure

  18. Case: Cows • 25 bred cows found acutely dead • 40 more animals showing clinical signs (400 cows in lot) • Some unable to rise • Some staggering, ataxic • Excessive licking/chewing motions • Decreased rumen motility • Rapid breathing, diarrhea

  19. Case: Cows • Normal diet included distiller’s slop • Last night, cattle were fed outdated product from by-products company • Sudden change in diet • Large amounts dumped into feed troughs • Poured on top of distiller’s grains remaining in troughs from previous day

  20. Case: Cows • 3,000 gallons of product • Dumped into 1st row of 500 gal troughs • 11 rows of troughs • Product fed at 8 PM • Found dead or affected animals at dawn • Affected animals were close to 1st row of troughs • Product contained the following: • Outdated Chocolate Nesquik Dairy ready-to-drink • Outdated Coffee Mate coffee creamer • Also a small amount of strawberry Nesquik drink

  21. Case: Cows • Ingredients in the Nesquik product: • Low fat milk, high fructose corn syrup, • <2% cocoa • 12 g total carbs per 100 gram of product • Ingredients of the coffee creamer: • Water, sugar, soybean or cottonseed oil, sodium caseinate, other ingredients • 29 g total carbs per 100 gram of product

  22. Case: Cows • Two cows brought to UKVDL for post-mortem • One dead, one euthanized after arrival • No obvious gross post-mortem findings • Differentials: • Acidosis • Over-eating • Methylxanthine (chocolate) toxicosis • Other??

  23. Case: Cows • Rumen pH: • 4.5, 4.8 • Estimated methylxanthine ingestion: • Not enough to likely cause poisoning • Examination of product: • Smelled like alcohol • Gas production on-going in container

  24. Case: Cows • Suspected Toxin: • Toxicologist’s Needs? • Toxin ID? • Toxin ID and Semi-Quantitation? • Toxin ID and Exact Quantitation? • Specimen for Analysis? • Brain, Liver, Kidney, Digestive Tract Contents • Body Fluids (Urine, Serum, Ocular Fluid) • Suspicious Bait or Bait Containers • Feed Ethanol

  25. Toxicology Tools X Microscopy X Ultraviolet / Visible Spectroscopy • Endpoint Reactions • Kinetic Assays X Liquid Chromatography X • Mass Spectrometry • Fluorescence • UV/Vis Absorbance Complexometric Reactions • Litmus Paper • “Dipstick” Tests X X Ion Exchange Chromatography Inductively Coupled Plasma • Mass Spectrometry • Atomic Emission Gas Chromatography • Mass Spectrometry • Flame Ionization Detection • Electrochemical Detection

  26. GC/MS Separates multiple components in a complex mixture over time: 1. Solvent Evaporation 2. Analyte-Column interactions 3. Detection at end of column

  27. GC/MS Gas Production in Container: Sample preparation minimized by using headspace injections Create A Calibration Curve Interpolate Concentration From Calibration Curve Quantitative Results Calibrant Solutions By-Product or Blood

  28. Case: Cows • Blood ethanol concentration in live cow: • 293 mg/dl • This concentration can be lethal in many species including humans • Study of cattle fed live brewer’s yeast: • Blood ethanol concentrations of 25 mg/dl were associated with severe intoxication • Ethanol concentration in feed sample: • 2,731 mg/dl • Diagnosis: • Ethanol poisoning

  29. Case: Ethanol Poisoning Possible sources of the ethanol: 1. Error by the by-products company • Wrong product delivered to tanker • By-products company also ferments products for fuel production in another location on the property

  30. Case: Ethanol Poisoning Possible sources of the ethanol: 2. Error by distillery • Distiller’s slops not properly distilled • Ethanol remaining • Unlikely -- fermentation still occurring • Distiller’s slops not properly heated to kill yeast • Sudden addition of fermentable carbohydrate from Nesquik product to left-over slops caused rapid fermentation and alcohol production

  31. Case: Steers • Over 4 weeks period, 15 steers in a group of 150 developed: • Acute onset of blindness, circling, running into things, ataxia, off feed, lethargic • Some died acutely • Some had signs for a few days before dying • Some had signs but recovered

  32. Case: Steers • Cattle fed soy hull creep feed and corn/soybean meal/soy hulls mix sold by a local feed company. • Company said no additional hay needed • A limiter was added to soy hull creep feed to limit intake • No exposures to anything new or unusual

  33. Case: Steers • Deaths occurred sporadically over a few weeks • Several veterinarians involved • Owner had seen cattle with these signs in past years, but never so many deaths

  34. Case: Steers • Differentials include: • Lead • Thiamin-responsive polioencephalomalacia • Salt intoxication • Listeria • Enterotoxemia • Coccidiosis • Vitamin A deficiency • Rabies • Sulfur-induced polioencephalomalacia

  35. Case: Steers • History: • Limiter used in the feed was calcium sulfate • Molasses used to make it stick to feed • In this case, 400 lbs of calcium sulfate per 5,000 tons of soy hulls • Very little hay was being fed • Post-mortems performed at LDDC: • Laminar cortical necrosis

  36. Case: Steers • Suspected Toxin: • Toxicologist’s Needs? • Toxin ID? • Toxin ID and Semi-Quantitation? • Toxin ID and Exact Quantitation? • Specimen for Analysis? • Brain, Liver, Kidney, Digestive Tract Contents • Body Fluids (Urine, Serum, Ocular Fluid) • Suspicious Bait or Bait Containers • Feed Excessive Sulfur

  37. Toxicology Tools X Microscopy X Ultraviolet / Visible Spectroscopy • Endpoint Reactions • Kinetic Assays X Liquid Chromatography X • Mass Spectrometry • Fluorescence • UV/Vis Absorbance Complexometric Reactions • Litmus Paper • “Dipstick” Tests X Ion Exchange Chromatography Inductively Coupled Plasma • Mass Spectrometry • Atomic Emission X Gas Chromatography • Mass Spectrometry • Flame Ionization Detection • Electrochemical Detection

  38. Case: Sulfur Poisoning • Feed samples analyzed for sulfur: • Soy hull creep feed: 2.3% sulfur • At 50% of the total diet, contributes 1.15% sulfur • Mixed feed: 0.19% sulfur • At 50% of the total diet, contributes 0.1% sulfur • Total sulfur in diet: 1.25% • Sulfur toxicity occurs at 0.2% - 0.4% • Diagnosis: • Sulfur-induced polioencephalomalacia (PEM)

  39. Case: Steers • Sources of excessive sulfur: • Calcium sulfate (gypsum) or other sulfur salts used as feed limiters • Increases risk of PEM by 40X • High sulfate water • Sulfur fertilization • Ammonium sulfate for urolith prevention • High sulfur feeds including: • Molasses • Distillers grains, corn gluten, other co-products

  40. Case: Steers • Prevention: • Restrict total dietary sulfur intake: • <0.3% for high roughage diets • <0.2% with high concentration rations • Evaluate total dietary sulfur before adding ammonium sulfate for urinary acidification • Avoid use of calcium sulfate (gypsum) • Avoid high molasses diets • Test co-product feeds before incorporating into diet. Test water sources

  41. In Closing: • Primary care veterinarian or extension veterinarian should be contacted • For any animal illness or sudden death • Many differentials possible • Sample selection and testing can be complex • If suspect intoxication, contact toxicologist before sending samples • Differentials, proper sample collection • Watch for new UKVDL website • Sample collection guidelines, other information

  42. Contact Information • Cynthia Gaskill DMV PhD • Phone 859-257-7912 • cynthia.gaskill@uky.edu

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