Pictured: Buttercup

Poisonous to: Cats, Dogs

Level of toxicity: Generally mild to moderate

Common signs to watch for:

  • Drooling
  • Vomiting
  • Diarrhea
  • Weakness
  • Blisters in the mouth or oral cavity
  • Weakness
  • Tremors
  • Seizures
  • Paralysis (rare)

Buttercup, of the Ranunculus family, is commonly called Butter cress and Figwort. These plants are found throughout the United States. Most are weeds found in overgrazed pastures, meadows, and fields. A few varieties are grown as ornamental plants. The plants contain the chemical ranunculin, which, when crushed or chewed, becomes the toxin protoanemonin. Protoanemonin is a bitter-tasting oil that irritates the mucous membranes of the gastrointestinal tract, and is poisonous to horses, cats, and dogs. The flower part contains the highest amount of toxin. Thankfully, buttercup generally doesn’t pose a serious threat because the toxin’s bitter taste and ability to cause mouth blisters limits the amount an animal will eat. However, poisoning can occur in overgrazed pastures where there are little to no other plants for horses to consume. When ingested, it can result in redness and swelling of the mouth, drooling, vomiting, diarrhea, and weakness. In larger amounts, ingestion by animals can result in blood-tinged urine, tremors, and rarely, seizures.

In horses, signs may not be seen for 1-2 days, depending on the amount ingested. Nose, lips, face, and skin may blister or swell after direct contact with plant. Blisters in the mouth, oropharynx, and esophagus also are common. Other signs include excessive salivation, an irritated gastrointestinal tract, colic, and bloody diarrhea. Tremors, seizures, and paralysis occur in rare cases.

Content written by: Dr. Lynn Hovda, DVM, RPH, MS, DACVIM, Director of Veterinary Services, Pet Poison Helpline

Poison type: plants

Alternate names: crowfoot, Ranunculaceae, Ranunculus, Butter cress, Figwort