Nandina Poisoning in Dogs

Nandina, although not in the bamboo family, is more commonly known as sacred or heavenly bamboo. It is a flowering evergreen shrub commonly used in landscaping which contains cyanogenic glycosides in unsafe concentrations in the berries. When eaten, cyanogenic glycosides convert into cyanide in the digestive system. If your pet has eaten any portion of this plant, it should be treated urgently. Sufficient quantities of cyanogenic glycosides can be fatal in less than an hour.

Nandina, also known as heavenly bamboo or sacred bamboo, is a flowering evergreen shrub with bright red berries. The berries contain cyanogenic glycosides, which convert to cyanide when digested.

Nandina plants contain a cyanogenic glycoside that is present throughout the plant but most concentrated in the bright red berries. Signs of cyanide toxicity generally occur within 15-20 minutes after consuming the berries.

• Cherry red blood
• Coma
• Dilated pupils
• Diarrhea
• Difficulty breathing
• Drop in blood pressure
• Excessive drooling
• Fluid accumulation in chest or abdomen
• Nausea
• Rapid heart rate
• Seizures
• Shock
• Smell of bitter almonds on breath
• Sudden death
• Tremors
• Vomiting

Types 

The Nandina plant is not the only plant that contains cyanogenic glucosides like nandinine. True bamboo (Bambusa arundinacea) contains the cyanogenic glucoside taxiphyllin in the young shoots, and sorghum (Sorghum vulgare) includes dhurrin. One of the more common cyanogenic glucosides found in nature is amygdalin. Amygdalin can be found in numerous fruits including the seeds and pits of:

• Apple 
• Apricot
• Bitter Almond 
• Cherry 
• Nectarine 
• Peach 
• Plum 

Other cyanogenic glucosides can also be found in plants that are commonly used as food sources such as the cassava root , the seed meal of flax , the giant taro leaf , and even Lima beans.

The toxin produced by the Nandina plant is a cyanogenic glycoside known as nandinine. Degradation of cyanogenic glycosides in the digestive tract produces hydrogen cyanide. Hydrogen cyanide is toxic in as little as two milligrams per kilogram of body weight for most animal species, although the concentrations in the nandina berries are relatively low. Death from cyanide poisoning is generally rapid, usually occurring in less than an hour from ingestion.

If your dog has ingested a plant that you believe to be a nandina plant, particularly if the berries were consumed, do not hesitate to contact your veterinarian. Cyanide toxicity from ingesting the berries of this plant can be rapidly fatal in large doses, and seeking early treatment is essential. Symptoms such as the smell of bitter almonds on the breath and cherry red blood, are somewhat unique to cyanide poisonings and will help confirm if the glycosides have been converted within the patient's system. Additional testing, including a complete blood count, urinalysis, and biochemical profiles, will be helpful in confirming your veterinarian’s suspicions. Cyanide can be detected in both the blood and the urine, but when cyanide exposure is suspected, treatment is often started without waiting for the result.

Due to the rapid progression of symptoms relating to cyanide poisoning, treatment should be initiated as soon as possible. Exposure to sufficient quantities of cyanogenic glycosides is likely to be fatal without prompt treatment, but swift and accurate treatment can greatly improve the prognosis. Amyl nitrate is commonly administered, generally accompanied by thiosulfate treatment in the form of an IV injection. Thiosulfate has been used independently with some success in situations where cyanide exposure is likely but unconfirmed. The antidotes to the cyanide that is produced in the gut are generally quite successful, as long as the heart is still beating. Caution is indicated in accurately dosing these chemicals as the antidotes are also toxic in their own right. 

Vitamin B12 may also be a useful addition to the treatment plan, as it is known to bind to the cyanide. When it binds to the cyanide molecule, it produces cyanocobalamin which is then excreted harmlessly with the animal’s urine. Additional treatments are supportive in nature and may include IV fluids to prevent dehydration as well as electrolytes and sugars to adjust for any imbalances. Oxygen therapy may also be helpful for your pet’s recovery. Administering oxygen has been shown to be especially useful for dogs and cats.

Untreated, significant cyanogenic glycoside ingestions are almost always fatal. If you are able to get your canine companion into the veterinarian’s office quickly, full recovery becomes much more likely. Prognosis once treatment has begun will depend on several factors, including the size of the dog, the quantity of toxin ingested, and the speed of initial diagnosis and treatment. Animals generally either recover or succumb within roughly two hours after symptoms start. It is possible for additional cyanide to be absorbed in the gastrointestinal tract after this time, causing a recurrence of the poisoning signs and symptoms. Your veterinarian will recommend a follow-up appointment as well, to check for any further complaints, particularly neurological disturbances, and behavioral changes.