The Importance of Veterinary Toxicology for Animal Agriculture and the Food Supply

1. The Importance of Veterinary Toxicology for Animal Agriculture and the Food Supply Birgit Puschner DVM, PhD, Dipl. ABVT California Animal Health and Food Safety Laboratory System School of Veterinary Medicine University of California, Davs

2. Belgium PCB and Dioxin Incident • In January, 1999, 500 tons of animal feed were contaminated with: • ~ 50 kg of PCBs and • 1 gramof dioxin Distributed to animal farms in Belgium

3. 1 storage tank of fat 2140 pork, poultry and beef farms 10 livestock feed manufacturers

4. Timeline of events • Feed contamination: January, 1999 • Early Feb, 1999: Veterinarian diagnosed chicken edema disease  prompted investigation • Mid March, 1999: • Feed and animal tissues were sent for tox testing • Veterinarian considered fat in animal feed the most likely source • April 26, 1999: Dioxin and PCB contamination confirmed by laboratory

6. 60 billion Belgian francs or ~ 1.5 billion U.S. dollars

7. Lesson learned… • Animal agriculture is an easy target • Toxicants can be widely distributed • Veterinarians may be the first responders • Veterinary toxicology laboratories are crucial in investigations •  Toxicology Case Studies

8. Poisoning Case in Dairy Cows • 22 – 24 lactating cattle died over a period of 9 days in a herd of ~ 300 cows • Affected cattle in one pen • Clinical signs: • Reduced or no rumen motility • Lethargic and hunched up • Decreased milk production • Increased respiratory rate and effort

9. ↓ Tongue tone • ↓ Palpebral reflex

10. Timeline • Consultation with herd vet: Day 1 • Necropsies: Day 2 • Hold placed on milk and milk products: Day 2 • Awaiting toxicology results • Awaiting possible danger to the food supply • Toxicology testing: Day 3-5

11. Oleander OP and carbamate insecticides Ionophore antibiotics (monensin, etc.) Toxic plants: tree tobacco, jimsonweed, poison hemlock, yews, larkspurs, lupine, foxglove, rhododendrons Hypocalcemia Hypomagnesemia Lead Arsenic, Mercury, Cadmium Copper Selenium GC/MS screen: pesticides, drugs, natural products FERN LC/MS screen: a large variety of chemicals that may result in high morbidity or mortality Rat poisons Toxicological Analyses Decision with regards to safety of milk & dairy products

12. Diagnosis of Botulism Type C – Source Challenges: Vagueness of clinical signs Tests for botulinum toxin not sensitive enough Tox testing crucial! Source of toxin Final Diagnosis – Day 7

15. March 2006

16. 47th and Stockton blvd

17. Cooked mushroom samples positive for alpha- and beta- amanitin. Mushroom pieces Onions

18. alpha-Amanitin beta-Amanitin Toxicology Involvement • Soup available for testing – rapid diagnosis • New methodology (LC/MS)

19. Poisoning Case in Dairy Cows • 6 lactating cattle (total in pen = 16) died within 24 hours in a herd of ~ 600 cows • “Just found dead” • Other information: • All animals are off feed a little • All animals on dairy get the same ration: TMR (corn silage and premix, top-dressed with hay) • Owner washed a spray tank the day before

20. Diagnostic Work-up • Necropsies: cardiotoxic event • Toxicology testing: oleandrin • GI contents, liver, muscle & feed • Serum, urine, milk Results within a few hours (LC/MS)

21. Benefit of Toxicology Testing • Rapid diagnosis • Testing of milk and meat

22. Perchlorate

23. Perchlorate • Developed LC-MS/MS method in 2 weeks • Method detection limit: ~ 0.8 ppb • 46 milk samples: • All samples were positive • 1.54 ppb to 20 ppb

24. Perchlorate Interlab Comparison Study

25. Perchlorate Regulatory Issues • NAS recommendation: 0.7 µg/kg/day • Drinking water equivalent level (DWEL) • 24.5 ppb for an adult • 4 ppb for infants • CA - Public health goal: 6 ppb

26. Perchlorate, Dairy Cattle and Human Health • Human health: • WHO – iodine deficiency • Rapid transfer of dietary perchlorate to milk • Perchlorate in dairy cows: • Ruminants – biofilters? • Perchlorate intake and milk iodide • Goal: limit perchlorate content of the dairy cow’s diet

27. Humans Thai food restaurant 107 affected people Methomyl exposure Insecticide Cases • Cattle: • Phorate • 167 deaths • Diagnosis established within hours • Analysis of milk and fat within hours

32. Methomyl • Testing of food, and food ingredients (oil, salt, herbs)

33. Mycotoxins • Aflatoxins • Fumonisins • Ochratoxin • Tricothecene mycotoxins • Penitrem A • Zearalenone

35. Algal Toxins Saxitoxins Anatoxins Microcystins

36. Importance • Testing for toxicants in a large number of matrices • Diagnosis of intoxications • Prevention of intoxications • Ensuring food safety • Assisting with risk assessments • Providing information to regulatory agencies

37. www.cahfs.ucdavis.edu

38. CAHFS Toxicology Laboratory • Member of FERN • Received funding through the Homeland Security Department • Largest Vet Tox Lab in the Country •  Highly trained personnel •  Continuous method development and expansion of existing testing