Candelabra Cactus Poisoning in Dogs

Euphorbia, commonly known as the candelabra cactus, is a species of spurge, a form of succulent that is used both as an indoor plant and as an addition to an outdoor garden in warm dry areas. All parts of the Candelabra cactus contain insoluble calcium oxalate crystals and these crystals can cause intense pain and irritation when chewed or swallowed. This irritation usually prevents animals from doing more than sampling the plant. On rare occasions, the dog may swallow larger amounts of plant material. On those occasions, your canine companion may require a visit to the veterinarian’s office.

The candelabra cactus (Euphorbia lactea) contains calcium oxalate crystals which can cause intense pain and irritation in the mouth and gastrointestinal tract when chewed or swallowed.

The Euphorbia family of plants contain insoluble calcium oxalate crystals in all parts of the plant. When chewed or swallowed these crystals can cause: 

• Cardiac arrhythmia
• Diarrhea
• Dilated eyes 
• Difficulty swallowing
• Excessive drooling
• Hoarse barking
• Labored breathing
• Loss of appetite
• Numbness of exposed area
• Obstruction of the airway
• Pawing/rubbing at the face or mouth
• Swelling of the tongue and lips
• Vocalization
• Vomiting

Types

The euphorbia lactea plant is a tropical shrub with tall, succulent type branches with short spines along the ridges. It most commonly called a candelabra cactus but also goes by the names mottled spurge, dragon bones, false cactus, hattrack cactus, milkstripe euphorbia and mottled candlestick. Several other types of plants contain insoluble calcium oxalate crystals which are the cause of irritation from euphorbia variety plants. These plants can include: 

• Arrowhead vine (Syngonium podophyllum)
• Calla or arum lily (Zantedeschia aethiopica)
• Chinese evergreen (Aglaonema modestrum)
• Devil’s ivy (Pothos, Epipremnum)
• Dumbcane (Dieffenbachia)
• Elephant’s Ear (Alocasia/Caladium/Xanthosoma)
• Flamingo plant (Anthurium)
• Fruit salad plant (Monstera)
• Jack-in-the-pulpit (Arisaema triphyllum)
• Peace lily (Spathiphyllum)
• Philodendron (Philodendron)
• Rhubarb (Rheum rhabarbarum)
• Skunk cabbage (Symplocarpus foetidus)
• Wild calla (Calla)

All parts of the Candelabra cactus contain the calcium oxalate crystals that cause the distress. Calcium oxalate is a calcium salt of oxalic acid which produces irritation and numbness to the tissues it comes in contact with. Chewing often causes immediate pain and inflammation to the mouth and throat as these crystals embed themselves in the soft tissues. If any of the sap or plant material is swallowed the irritation can extend to the throat and down through the GI tract, causing swelling and severe pain. The swelling can sometimes cause breathing difficulty if the airway is blocked.

Many of the symptoms of exposure to the calcium oxalate crystals from the euphorbia plants will present very quickly so identification of the plant is usually all that is required for diagnosing the cause of agony. Symptoms have been known to take up to two hours to show up. If you did not observe what your pet ingested, or if your dog ingested large amounts of the plant material, your veterinarian may recommend a visit to the office. The veterinarian will want to take special note of concurrent supplements or prescriptions that your dog is on. If you think your pet may have ingested a plant of any kind while in your yard or at the park on a walk, let the veterinarian know. A complete blood count, biochemistry profile, and urinalysis will likely be done at this point as well in order to reveal any concurrent diseases or disorders. If your dog has ingested enough of the plant material that they are vomiting, then the vomitus will also be examined and tested for toxins. Plant material in the vomit may help confirm the diagnosis.

Immediate treatment will start with a thorough rinsing of the mouth and affected areas with clean and cool water to remove as many of the microscopic crystals as possible. You may also want to offer your dog very cool water in his dish to ease the pain until you are able to contact your veterinarian. The discomfort and unpleasant taste will usually prevent most canines from ingesting much of the actual plant material, so rinsing the mouth area may be all that is required. In certain circumstances, your veterinarian may also recommend giving your dog an appropriate pain reliever or antihistamine. 

If a larger amount of the plant material or sap was ingested, a visit to the veterinarian’s office may be needed. IV fluid treatment will be offered to prevent dehydration, and if an antihistamine was not previously administered it is likely to be administered at this time as an intramuscular injection. Gastro-protective medications may also be recommended to prevent damage to the lining of the stomach. If the airway is significantly swollen your canine may need to be kept under observation at the office until the swelling subsides.

Prognosis for dogs affected by ingesting smaller amounts of the plants containing the calcium oxalate crystals, such as the candelabra cactus, is usually quite good. The painful effects of the crystals in the mouth and gastrointestinal tract usually dissipate within twelve to twenty-four hours from ingestion, although swelling in the airway will need to be evaluated by a veterinarian. Massive doses of calcium oxalate crystals are rare due to the initial pain and discomfort in the mouth. When larger doses do occur they can cause liver and kidney damage so the liver and kidneys may need further monitoring in the event of the ingestion of substantial quantities of the sap.