Poisonous Plants

1. Poisonous Plants Clif Little Associate Professor OSU Extension Noble/Guernsey Counties 740-489-5300 or 740-732-5681 Technical reference source: University of Pennsylvania's Poisonous Plants Home Page, http://cal.vet.upenn.edu

2. Types of Poisons • Thiaminases • Interfere with thiamin (B1) utilization • Loss of condition, unthriftyness • Endophytes • Symbiotic usually beneficial to the plant • Varied effects

3. Types of Poisons, cont’d • Alkaloids • Contain nitrogen • Affect CNS • Glycosides • Non-sugar group combined with glucose • Often cyanogenic, hydrocyanogenic (HCN)

4. Types of Poisons, cont’d • Photosensitizing substances • Cause severe reactions to sunlight • Organic Acids • Oxalic and tannic most common • Weakness, incoordination, and death.

5. Types of Poisons, cont’d Nitrate • i.e. corn-silage, pigweed,etc. Mycotoxicoses, -- moldy grain Mineral, -- ex. High k or water contamination Insect, -- ex, blister beetle

6. Fall Grass

7. Bracken Fern • Not extremely common in Ohio. • Leaves and rhizomes, fresh and dried (hay) • Thiaminase activity 2-4 weeks continuous grazing • Lose condition, unthrifty, anorexia, reduced bone marrow activity, blood in urine. • Recover with support.

8. Tall Fescue • Very common pasture and hay grass. • Endophytic fungus • Late gestation mares, prolonged gestation, abortion, weakened foals. • Research suggesting decreased efficiency in growing farm animals.

9. Perennial Ryegrass • Very common in Pastures and Hay. • Endophytic fungus. • Less danger if Kept Vegetative. • “Staggers” – head tremors, nodding movements, incoordination.

10. Poison Hemlock • All parts of plant • Most toxic when fresh/growing • Odor usually prevents consumption. • alkaloids • Dilated pupils, weakness, staggering, respiratory paralysis within hours.

11. Water Hemlock • One of most poisonous plants in Ohio • All parts of plant, toxic • Symptoms, colic and convulsions, respiratory failure, within 30 minutes • Death within hour

12. Jimsonweed • Common around Barn. • All parts, including seeds, tropane alkaloid. • Strong odor, taste, usually not consumed fresh. • Can be in Hay, or grain • Within minutes, weak thready pulse, incoordination, convulsions, excessive thurst. • Can result in death.

13. Hemp Dogbane • Indian Hemp, Snake’s Milk • Leaves and stems, glucoside, alkaloids • Fresh and dry • Less than 1 ounce is fatal • Increased temperature, pulse, discolored membranes, anorexia, death

14. Common Milkweed • Warm, dry soils, with sunlight • All parts, green or dried, steroid glycoside. • Within few hours of ingestion. • Incoordination, loss of muscle control, thready pulse. • Rarely death

15. Nightshade Family • Glycoalkaloid, Solanine • GI irritation, CNS problems • Acute hemorrhagic gastroenteritis • Weakness, incoordination, difficult breathing. • Death • Eastern Black Nightshade, Bittersweet Nightshade, Horse Nettle, Groundcherries.

16. Eastern Black Nightshade • Widespread in Ohio • Found in open, disturbed habitats Other relatives

17. Groundcherries • 7 species, smooth most common. • Leaves and unripe fruit toxic. • Found in both cultivated, reduced tillage and pasture/hay fields.

18. Horsenettle • A.K.A. Bull Nettle, Devil’s Potato • Found in pastures/hay. • Many animals avoid eating leaves but will eat berries. • Most toxic in late summer to fall.

19. Johnsongrass • Plant Stress results in cyanide production (HCN) • Within minutes – excitement, incoordination, convulsions, labored breathing, bright red venous blood. Death due to respiratory failure. • Chronic poisoning – nerve damage. • Young shoots when wilted, hay not usually a problem. • Nitrate poisoning also possible – GI irritation, hypoxia. • Similar grasses – Sorghum/Sudangrass, Reed Canarygrass.

20. Sweetclover • legume • Mold is problem, usually in hay or silage, no problem when grazed. • Several weeks before problems are seen. • Coumarin is converted to Dicumerol. • Hemorrhages • Crosses placenta – abortions • Treatment vit-K

21. Oaks • Red Oak,Tannins • Young leaves, sprouts, acorns. • Water in which leaves soak. • GI and renal dysfunction • Colic, anorexia, constipation, jaundice • Death can occur. Gallotoxins from Tannic & gallic acid

22. Buckeye • Several species • Glycosides, saponin, alkaloids. • Sprouts, leaves, and seeds. • Depression, incoordination, twitching, excessive salivation, colic. • Many animals may survive with care.

23. Black Locust • Several toxic compounds, & toxic protein “Robin” • Sprouts, leaves, bark. • Soaks into water • Stand with base-wide, depression, diarrhea, anorexia, weakness, paralysis, colic, laminitis. • Severe cases, death from cardiac failure.

24. Fruit trees • Wild Black Cherry, Peach • Seeds, twigs, bark, leaves • Frosting causes cyanide to form. • Consumption of water shortly before Cherry increases reaction. • Excitement, incoordination, convulsions, death from asphyxiation, Red Mucosa.

25. Yews • Ornamental, clippings are not good feed. • Leaves, bark, seeds ARE ALL POSSIBLE SOURCES OF TOXINS. • Green or dry can cause problems.

26. Preventing Poisonings • Know which are dangerous, and when • Inspect pastures • Ensure horses not hungry/thirsty • Buy hay locally • Maintain appropriate grazing pressure • Provide supplemental feed as necessary

27. Conclusion • No known treatment for many plant poisonings • Supportive treatment may help in early stages, but problem often not realized until it’s too late. • Prevention is best form of control

28. Ornamental Plants Many ornamentals are toxic • Livestock will readily eat. • Lupins, foxglove, holly, daffodils, hyacinths, azalea, rhododendron.

29. Elderberry • Shoots, leaves, bark • HCN poisoning • Bright red mucosa, anxiety, staggering, breathing difficulties.

30. Red Maple • Consumption of wilted leaves. • Dried leaves toxic up to 30 days • Symptoms within 3-4 days • Hemolytic anemia, methemoglobinurea, destruction of red blood cells. • Rapid breathing, heart rate, cyanosis, brown urine, death.

31. Black Walnut • Jugulone in bark, wood, nuts, roots. • Primary problem with shavings in bedding. • Laminitis • Depression, lethargy, increased temp., pulse, respiration, colic. • Signs clear up if removed.

32. Mustards • Very common • Seeds and vegetative parts contain toxin, glucosinolate • Mustard oils also irritant. • Anorexia, severe gastro-enteritis, salivation, diarrhea, photosensitization, goiters.

33. Amaranth • Pigweed, Lambsquarter • Nitrate • Breathing difficulty, chocolate blood, old are stricken first, abortions may occur.

34. Common Cocklebur • Very Common • Glucoside • Seeds & roots most toxic, seldom consumed. • Young leaves, & root are toxic. • Rapid pulse,Colic, anorexia, depression. • Survivors usually have chronic liver disease.

35. buttercup Severe gastrointestinal irritation

36. Common Pokeweed • Common around barns and fence rows, contains saponins. • Horses WILL NOT AVOID • Roots and leaves • Excessive salivation, colic, bloody diarrhea, birth defects • Severe toxicity, respiratory failure.

37. Field Horsetail • Common horsetail found along streams. • Difficult eradicate. • Green more toxic, but more problems in hay. • Thiaminase activity similar to Bracken Fern, except maintain appetite • Also excitability, staggering, emaciation.