Castor Bean Poisoning in Dogs

This plant is a member of the Euphorbiaceae family with broad red or green lobed leaves that grow spikes with red and yellow flowers. Fruit pods with three seeds in each also grow on this spike. Castor bean plants contain ricin, one of the most potent toxins in the natural world. It is present in very small amounts throughout the plant, but the greatest concentrations are in the seeds. The seeds are often found in jewelry as well due to their attractive mottled brown appearance. The castor bean plant is also the source of castor oil and is often grown for oil production, and is used as a decorative plant in gardens and parks. It also grows wild in southern California and parts of Florida.

The seed of the castor bean plant contains ricin, one of the most potent toxins in the natural world. If your pet ingested seeds from this plant, contact your veterinarian immediately.

Symptoms of ricin poisoning from castor beans in dogs can occur anywhere from six hours to up to 42 hours after ingestion.

• Abdominal pain
• Abdominal straining
• Bloody diarrhea
• Death
• Dehydration
• Excessive drooling
• Hypotension (drop in blood pressure)
• Increase in body temperature
• Loss of appetite
• Pain in mouth
• Sudden collapse
• Trembling
• Vomiting
• Weakness

Types

The castor bean plant is one of several that utilize plant lectins, a type of glycoprotein known for their ability to induce clumping in red blood cells. Although the castor bean plant is the only one containing ricin itself, the related plants are also quite toxic. Other plants that have toxic lectins include:

Abrus precatorius (Toxin: Abrin)

• Akar Saga
• Crab's eye creeper
• Gidee gidee
• Indian licorice
• Jequirity
• John Crow bead
• Jumbie bead
• Paternoster pea
• Red-bead vine
• Rosary pea
• Weather plant

Canavalia ensiformis (Toxin: Concanavalin A)

• Jack bean

Robinia pseudoacacia (Toxin: Toxalbumen robin)

• Black Locust tree

The cause of the toxicity in the castor bean plant is a protein called ricin. Ricin, only found in the castor bean plant, is one of the most poisonous substances to occur in nature. Although the ricin is present throughout the plant, it is most concentrated in the seeds of the plant, often referred to as castor beans. Castor beans are an attractive mottled brown and are used throughout the world to make jewelry and rosaries. It would take a great deal of plant material to be detrimentally toxic to your dog if no seeds were ingested. The concentration of ricin in the seed itself makes the seeds much more treacherous than the rest of the plant. Artisans creating jewelry have lost their lives due to accidental ingestion of the powder that escapes when holes are drilled into the seeds and due to pricking their fingers with the contaminated needles. If your dog ingests the seeds without chewing there is a chance that the seeds will pass through the system with no ill effects. If the beans are chewed or broken, or if they have drill holes from being made into jewelry, then the toxin is released from the shell.

If you believe your pet has ingested any castor beans do not hesitate to contact your veterinarian. Ricin toxicity from ingesting castor beans is often fatal even with aggressive treatment so seeking that treatment early is the best course of action for a positive outcome. If you see your pet consuming the seeds from a castor bean plant identification is often all that is required for diagnosing the origin of your pet’s difficulty. If you didn’t happen to witness the ingestion of the plant your veterinarian will take note of any instances you can remember whereby your pet may have been digging in the garden, in addition to any concurrent prescriptions or supplements that your dog may have been prescribed in an attempt to determine which drug or toxin is causing the symptoms. A biochemistry profile, complete blood count, and urinalysis may be ordered at this time, including an immunoassay to detect the substance in either the blood or urine if ricin poisoning is suspected.

There is no antidote to ricin, either for canines or for humans, however, supportive therapy is needed to give the patient a chance at survival. Because of the severity of the poison, your dog is likely to be admitted into the veterinary hospital immediately upon diagnosis. If the time since ingestion has only been a few hours your veterinarian will probably start with a gastric lavage which is usually done with the use of general anesthetic. Activated charcoal will most often be given to your pet at this point to soak up as much of the toxin as possible. The supportive treatment will include IV fluids for dehydration as well as electrolytes and sugars to adjust for any imbalances. Oxygen should also be given to the dog if breathing is becoming difficult, and pain management medications may also be administered. Ricin tends to be particularly injurious to the liver and kidneys and hepatoprotective medications are often warranted in addition to gastroprotective measures. Generally, a human with ricin poisoning will either recover or succumb within 36-72 hours, although canines appear to be very slightly more resistant than humans so this can extend the hospital stay by a few days compared their human counterparts.

Prognosis of recovery from ricin poisoning is guarded, at best, and is influenced by the dose ingested, the size of the dog, and the speediness of supportive treatment. If your pet recovers from the toxin, a calm and quiet atmosphere when they return may help speed full recovery. Internal organs are often permanently scarred from the poison, and more frequent testing to monitor liver and kidney function may be required. The best way to prevent damage is to avoid exposure. Ensure that any jewelry containing castor beans is kept out of reach of both pets and children, and be aware of the plants presence in parks and landscaping. If you grow castor bean plants in your garden it is best to limit your companions access to it, and cutting the seedpods and safely disposing of them before they are able to release seeds will greatly reduce the risk to your pet.