Monkshood Poisoning in Dogs

Monkshood refers to a genus of plant with the scientific name of Aconitum. It displays glossy green leaves and a uniquely shaped flower with five petals, the uppermost of these a modified hood-shaped petal. It is also commonly referred to as wolfsbane, mousebane, devil’s helmet, and queen of all poisons. Although poisonings by monkshood are rare due to the smell and taste of the plant, they are quite dangerous when they occur. The poison that is produced by aconitum plants interferes with the regulation of the sodium ion channels in the muscle cells, and if untreated it is often fatal. If your dog ingests any amount of monkshood contact your veterinarian or the nearest emergency clinic as soon as possible.

Aconitum plants, commonly known as monkshood or wolfsbane, contain a deadly toxin known as aconitine. If your pet has ingested any part of this plant it should be treated as an emergency.

Monkshood flowers are visually a treat, but they don’t smell very attractive. They also taste unpleasant and cause burning sensations in the mouth when chewed. For these reasons accidental poisonings from monkshood remain fairly rare even though the toxic dose is small. Symptoms of poisoning from this flower can include:  

• Abdominal pain
• Frothing at mouth
• Heart arrhythmias
• Numbness
• Paralysis
• Pawing at mouth
• Seizures
• Shallow breathing
• Tremors
• Vomiting
• Weakness

Types

Aconite is extremely well known for its toxic properties and has been for centuries. Poisonings with wolfsbane have been referred to in Greek mythology, in Shakespearian plays, and in modern literature. Its healing properties are not as well known due to the risks involved with employing them. In the past, it has been used as a pain reliever and fever reducer. However, the difference in amount between a therapeutic dose and a deadly dose is small, making calculating the appropriate dosage tricky. The toxin in aconite, the aconitine, can still be found in minuscule amounts in some herbal medications. If your pet ingests any herbal remedies or supplements meant for humans, bring the bottle with you to the veterinarian’s office as the ingredients used could turn out to be detrimental to your pet.

The toxicity of this plant lies in the alkaloid it produces, called aconitine. This toxin binds to the receptors of the cells that regulate the muscle cells’ sodium ion channels. This causes paralysis in the affected cells. A very potent poison, ingestion is not required for it to be fatal as it can be absorbed through any mucous membrane or even enter the bloodstream through a break in the skin. Even water in which plants in the Aconitum family have been soaked can also be deadly to consume.

If you believe your pet has ingested or otherwise been exposed to monkshood toxin, do not hesitate to contact your veterinarian. Toxicity from aconitine exposure can be fatal in less than an hour, so seeking treatment early is the best course of action for a positive outcome. If you happen to witness your pet’s ingestion of the aconite plant, then the identification of the plant in question is often all that is required for an initial diagnosis.

If you didn’t happen to witness the ingestion of the plant, your veterinarian may ask questions about unusual behavior that was observed, or the consumption of forbidden foods or substances that you suspect your pet may have sampled. Alert your veterinarian to any concurrent prescriptions or supplements that your dog is taking as this can help determine which drug or toxin may be causing the symptoms. A biochemistry profile, complete blood count (CBC), and urinalysis are likely to be completed at this time. This may include an immunoassay to detect the substance in either the blood or urine if aconite poisoning is suspected.

Because of the severity of the poison, your dog is likely to be admitted to the veterinary hospital immediately upon even a preliminary diagnosis. There is no specific antidote to aconitum, either for canines or for humans. Timely supportive therapy is indispensable to give the patient their best chance at survival. If the time since ingestion has only been a few hours, your veterinarian will probably use a gastric lavage to remove as much plant material from the digestive system as possible. Activated charcoal will most often be given to your pet at this point to soak up as much of the toxin as possible. General supportive treatment for poisoning includes intravenous fluids to prevent dehydration as well as administration of electrolytes and sugars to regulate any imbalances that may occur. Oxygen should also be given to the dog if breathing is becoming difficult, and pain management medications may also be warranted. 

Victims of aconite poisoning usually either recover or succumb within approximately 24 hours. A calm and quiet atmosphere is paramount in helping a patient recover from the poisoning caused by monkshood as stress to the heart should be avoided. The best way to prevent damage is to avoid exposure. Be aware of these plants in your environment. They can be found in the wild mostly in the mountainous regions of the northern hemisphere, and may also be present in parks and in landscaping. If you choose to grow monkshood in your garden, always use gloves when working with the plant and ensure that the plant, gloves, and gardening tools are all inaccessible to any pets and children.