Exotica Poisoning in Dogs

The exotica is a tropical plant in the Araceae family displaying large flat leaves with attractive white markings. All parts of the exotica plant contain microscopic calcium oxalate crystals that can cause extreme pain and irritation when chewed or swallowed. The penetration of the skin and mucous membranes by the sharp crystals usually prevents animals from doing more than sampling the plant. On rare occasions, the dog may ingest larger amounts of plant material. On those occasions, your canine companion will most likely require a visit to the veterinarian’s office.

The exotica plant (Dieffenbachia amoena) contains insoluble calcium oxalate crystals which can cause intense irritation and stabbing pains in the mouth and gastrointestinal tract when chewed or swallowed.

The exotica plant contains insoluble calcium oxalate crystals in every part of the plant. When chewed or swallowed these crystals can cause: 

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

Types

The Dieffenbachia amoena plant is an attractive, broad-leaved tropical plant conspicuous white markings. It most commonly called charming dieffenbachia but is also referred to by the names exotica, tropic snow, and dumb cane. Other plants in multiple plant families contain insoluble calcium oxalate crystals, which are the primary cause of irritation from euphorbia variety plants. These plants can include: 

• Arrowhead vine (Syngonium podophyllum)
• Calla or arum lily (Zantedeschia aethiopica)
• Candelabra cactus (Euphorbia lactea)
• Chinese evergreen (Aglaonema modestrum)
• Devil’s ivy (Pothos, Epipremnum)
• 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)

The calcium oxalate crystals that cause distress to curious animals are contained in all parts of the exotica plant. Calcium oxalate is a calcium salt of oxalic acid which produces irritation and numbness to the tissues it contacts. Chewing any portion of the exotica plant usually causes immediate pain and inflammation to the mouth and throat as the tiny crystals hidden in the sap are thrust into the soft tissues that they come into contact with. If the sap or plant material is swallowed as well, then the irritation will extend into the throat and down through the GI tract, causing inflammation and severe pain. Swelling in the throat can also obstruct the airway, resulting in breathing difficulties.

Dogs that chew on plants with insoluble calcium oxalate crystals (such as the exotica plant) will often develop the initial symptoms within just a few minutes, making the identification of the plant sufficient for an initial diagnosis of the origin of the condition. Symptoms have occasionally been known to take up to two hours to show up, particularly if the plant material was swallowed before chewing took place. If you did not observe what your pet ingested, or if sizeable quantities of plant material were consumed, your veterinarian would most likely  recommend that you bring your animal in for a visit. 

Your dog's doctor will get any information from you about any opportunistic eating in addition to any concurrent supplements or prescriptions that are being administered to your dog. A biochemistry profile, complete blood count, and urinalysis are will usually be done during the physical exam in order to reveal any concurrent diseases or disorders, including other possible toxins.

Thoroughly rinsing out the mouth and affected areas with fresh, clean water will remove a significant portion of the irritating crystals from the surface areas. You may also want to offer your canine something cooling to eat or drink, such as ice cubes or milk, to ease the oral discomfort and pain until you are able to contact your pet’s doctor. The pain, coupled with the unpleasant taste, usually prevent inquisitive animals from consuming much of this plant, so rinsing the mouth area may be all that is required in milder cases. Your veterinarian may also recommend an appropriate pain reliever or antihistamine for your dog if the swelling or pain become too distressing.

If your veterinarian recommends that you bring your pet into the office due to the amount ingested or the severity of symptoms, then IV fluid treatment will be offered to combat dehydration and chemical imbalances. If an antihistamine was not administered before bringing the animal in, it would probably be provided as an intramuscular injection at this time. Gastroprotective medications may be suggested to help prevent damage to the stomach lining. If the airway is significantly swollen, your canine will need to be kept under observation at the office until the swelling subsides, and may need to be intubated in order to provide oxygen.

Dogs affected by ingesting small to moderate amounts of the plants containing the insoluble calcium oxalate crystals, such as the exotica plant, usually recover completely. Generally, the painful effects of the crystals have dissipated from the mouth, throat, and gastrointestinal tract within twelve to twenty-four hours from ingestion. Any swelling of the airway will need to be evaluated and treated by a veterinarian, even if other symptoms are mild. Large doses of calcium oxalate crystals are rare due to the initial pain and discomfort in the mouth, however, when massive ingestions do occur they can cause liver and kidney damage. This means that the liver and kidneys may need further monitoring in the event of the ingestion of substantial quantities of the sap.