Poison Hemlock

Identifying Characteristics:

• Low growing rosette first year of lifecycle
• 3-8 ft tall second year of lifecycle
• Alternate compound leaf pattern
• Fern-like leaves
• Purple blotches on stem
• Produces white flowers and seeds during its second year

Plant Longevity:

• Biennial

Where Commonly Found:

• Fence rows
• No till fields
• Pastures
• Wood lines
• Roadsides
• Waste areas

Time of Most Concern:

• Young plants in the spring

Compound that Causes Concern:

• Coniine
• Coniceine

Part of Plant Most Toxic:

• All parts of the plant are toxic, however, younger plants and seeds are most toxic

Livestock Species Affected:

• Cattle
• Goats
• Swine
• Horses
• Sheep
• Poultry

Pasture, Stored Feed, Both:

• Both

Clinical Signs:

• Acute
  • Nervousness
  • Seizures
  • Dilated pupils
  • Excitation
  • Drooling
  • Slowed breathing
  • Irregular heartbeat
  • Frequent urination
  • Muscle tremors
  • Weakness
  • Depression
• Chronic
  • Birth defects such as twisted limbs, scoliosis, twisted neck, or cleft palate
    • Cattle must ingest the plant at between 40-70 days of gestation for birth defects to occur
    • Sheep and goats must ingest the plant at between 30-60 days of gestation for birth defects to occur

Amount Needed to be Consumed for Clinical Signs / Death:

• Signs depend on amount consumed
• Signs appear 30 minutes to 2 days after consumption
• 10-16 oz in cattle