Pencil Cactus Poisoning

CactusThe Euphorbiaceous family of plants has many branches that cause a toxic reaction when trimmed and the sap spills out, or in the case of pets, when the plant is bitten into. Most of the documentation available refers to human poisoning by pencil cactus, but the risk is indeed there if you have this plant in your garden within reach of a curious pet. The pencil cactus will cause immediate pain when bitten into which serves as a deterrent for large ingestions of the plant. However, the dermal, and particularly the ocular damage that has been recorded in humans can easily be related to the animal species if exposed to the plant’s toxic sap. Milky sap can be released from any part of the plant, resulting in symptoms like stomach pain upon ingestion or burning of the eyes if the exposure is of an ocular nature.

Symptoms of Pencil Cactus Poisoning in Dogs

You may see the following signs of distress in your pet if he/she comes into contact with the pencil cactus.

Ocular Contact

  • Pain Swelling
  • Redness
  • Ulceration
  • Temporary or permanent blindness (some humans have experienced permanent blindness)

Dermal Contact

(There can be a delay in dermal symptoms)

  • Burning
  • Blisters
  • Rash accompanied by pain
  • Irritation to the skin


  • Stomach pain
  • Vomiting
  • Nausea
  • Diarrhea

There are thousands of types of plants in the Euphorbia genus. The pencil cactus is also commonly called the following names. Milk bush, Pencil tree, Finger tree, Rubber Euphorbia Indian spurge tree, Fire stick plant.

If your pet comes into contact with this plant/sap please seek veterinary care immediately