Poisonous Plants

Cherry (prunus)

  • Cherry
  • Wild Black Cherry
  • Chokecherry

Source of Toxicity:

  • Cyanide in seeds, leaves, bark and fruit (highest to lowest concentrations).
  • Toxic when plant is stressed - wilting caused by frost, storm damage, cutting, trampling.

Symptoms:

  • Tremors
  • Gasping for breath
  • Sudden death
  • Blood is bright red as cyanide prevents hemoglobin from releasing oxygen

Prevention:

  • Don't leave cherry branches in pasture, don't feed after frost or damage, sorghum is safe if 2 ft. or taller, silage fermentation eliminates poison.

Other cyanogenic plants:

  • Sorghum
  • Johnson grass
  • Flax
  • Arrowgrass
  • White clover
  • Milkweed
  • Black Locust
  • Horse chestnut
  • Dogbane

 

Yew (Taxus)

Source of Toxicity:

  • Whole plant is extremely toxic except the red fruit.
  • Used in hedges as an ornamental, clippings are deadly.

Symptoms:

  • Trembling
  • Muscle weakness
  • Collapse
  • Sudden death
  • Taxine alkaloid in plant stops the heart.

Prevention:

  • Never feed clippings
  • Make sure grass clippings don't have yew
  • Animal should not be able to reach yew from fence or pasture

Treatment:

  • Activated charcoal
  • Atropine
  • Calcium
  • Do not stress exposed animal

Others:

  • Boxwood
  • Privet

Rhododendron

  • Azaleas
  • Laurels

Source of Toxicity:

  • All parts, especially leaves
  • Flower nectar, including honey made from nectar

Symptoms:

  • Salivation
  • Vomiting
  • Diarrhea
  • Weakness
  • Slow heart rate
  • Staggering
  • Convulsions
  • Vocalization
  • Possible death

Prevention:

  • Keep hungry animals away from growing plants
  • Do not use in hay
  • Use caution when placing beehives

Treatment:

  • Mineral oil and activated charcoal may be given orally to absorb toxin
  • Fluids and pain relief
  • Veterinary attention

Other Toxicities

Nitrogen containing ring compounds nitrogen that are common to about 15 to 20% of all vascular plants with a characteristic bitter taste. Alkaloid containing plants include: Nightshade, Jimsonweed, Horse Nettle, Black Snake Root, Lupines, Monkshood, Water and Poison Hemlock, Mayapple, Pokeweed

 

Photodynamic chemicals accumulate under skin and react to sunlight on unpigmented areas of the skin. This can lead to swelling, irritation and secondary infections. (Photosensitizing plants include: St. John's Wort, Latana, Buckwheat, Rape, Kale, Ragwort, wild carrots, Goat weed, Klamath weed)

 

When high amounts of nitrate are consumed, an accumulation of nitrite may occur in the rumen. Nitrite will be absorbed into the bloodstream and coverts hemoglobin to methemoglobin, which is unable to transport oxygen. The animal dies from a lack of oxygen and the blood will have a dark chocolate color. (Nitrate poisoning is associated with: sorghum and Sudan grass, oats, beet tops, rape, soybean, pigweed)