Virgin's Bower in Dogs

Vines in the clematis genus are also referred to as virgin’s bower, leather flower, and old man’s beard. The clematis genus belongs in the buttercup family Ranunculaceae, and like other plants in the Ranunculaceae, all parts of the clematis plants contain various cardiac glycosides as well as ranunculin, a glucoside which breaks down into the toxin protoanemonin in the digestive system. Collectively, these compounds can cause symptoms from drooling to neurological and cardiac disturbances. Fortunately, this plant is quite unpalatable, making severe poisonings exceptionally rare.

Virgin’s bower vine refers to one of 300 or so climbing vines with woody stems in the Clematis genus. This vine contains several compounds that render it moderately toxic.

In most cases, very little of the plant material is actually ingested, and the symptoms remain mild. Substantial amounts of the plant would be required for major toxicity to develop and, in most cases, not enough material is ingested to trigger the more alarming of the possible symptoms.

Symptoms caused by protoanemonin consumption can include:

• Abdominal pain
• Blistering of the mouth and throat
• Bloody or tarry stools
• Difficulty chewing
• Dizziness
• Diarrhea
• Excessive drooling
• Hepatitis
• Jaundice
• Nausea
• Pawing at mouth
• Spasms
• Vomiting

Poisoning from glycosides usually involves the central nervous systems as well as the cardiac muscle, and can add symptoms like: 

• Abnormal heart rate
• Cardiac arrhythmias
• Collapse
• Confusion
• Depression
• Dilated pupils
• Disorientation
• Lethargy
• Seizures
• Sudden death
• Tremors
• Weakness

Types 

Virgin’s Bower can be used to refer to the entire clematis genus, although certain species are more likely to be referred to by this label than others. A few of the varieties that commonly use the title of virgin’s bower include:

• Clematis columbiana - British Columbia virgin's bower
• Clematis crispa - curly virgin's bower
• Clematis flammula - fragrant virgin's bower
• Clematis occidentalis - western blue virgin’s bower
• Clematis virginiana - Virginia virgin’s bower

The most commonly cultivated Clematis of this small group is the clematis virginiana, or Virginia virgin’s bower, which grows throughout the eastern half of North America.

There are two categories of toxin at work with the virgin’s bower vine; cardiac glycosides which are found in several plant families, and a glucoside called ranunculin found exclusively in plants in the buttercup family. The ranunculin breaks down into the toxin protoanemonin as it decomposes, and it decays rapidly when the plant is damaged. This toxin is responsible for the pain and blistering that occurs when the plant is first ingested, and if substantial amounts are ingested, bleeding in the digestive tract. The glycosides, on the other hand, affect the cardiac and central nervous systems. It is somewhat rare for the glycosides in the virgin’s bower vine to have an effect, as the unpleasant taste, the pain, and the burning tends to discourage most animals from eating substantial enough quantities to cause symptoms to develop.

Reactions to these plants are generally relatively mild unless large volumes of the plant are eaten. If the symptoms become severe, a sample of the plant should be brought with you to the veterinarian’s office if possible, in order to confirm the identification of the plant. If the signs and symptoms are incongruent with clematis poisoning, or if the eating of the plant was unwitnessed, then the diagnostic procedure may be more involved. Your veterinarian will generally order a biochemistry profile, complete blood count, and urinalysis when you visit the clinic, with an emphasis on heart rhythm and function.

A history of your pet’s health will also be needed, as well as information regarding any medications or supplements being administered to your pet.  Drugs such as steroids, beta-blockers, and some chemotherapy agents may interact negatively with the cardiac glycosides present in the Clematis genus of plants. Tests to check the functionality of the kidneys and the liver are also helpful in determining if any impairment has occurred with either organ.

Prognosis will be dependent how much was consumed, the size of the patient, and what symptoms are being exhibited. The first order of business should be a thorough rinsing of the mouth, particularly if your pet is showing signs of burning or pain in the mouth or throat area. If it has been less than a few hours, and the amount eaten was not overly large, your veterinarian may give you instructions on how to safely induce vomiting in your dog, usually using hydrogen peroxide. If hefty quantities of the plant were consumed, or if critical symptoms are starting to develop, a visit to the veterinary clinic may be required for further treatment. 

Gastric decontamination is often needed to void the many alkaloids from the canine’s system, after which activated charcoal is utilized to soak up as many of the remaining toxins as possible. Treatment after decontamination is generally supportive. IV fluids will be required to fight dehydration as well as to ensure that the proper electrolyte and sugar balances are maintained. Calcium should be avoided as an additive to IV fluids with poisoning caused by virgin’s bower as calcium has a tendency to enhance the effects of the cardiac glycosides. If symptoms expand to include cardiac involvement, then antiarrhythmic drugs such as procainamide, atropine sulfate, or lidocaine may be used in an attempt to regulate the heart rate.

Severe toxicity due to clematis ingestion is rare due to the unpleasant taste and the burning and itching in the mouth, caused by the ranunculin in the plant. Most symptoms from eating this genus of plants will dissipate within 24 hours. If the quantities ingested or the symptoms necessitate a stay at the veterinary clinic, a quiet and calm environment should be available for your pet to speed recuperation. This is of particular concern if the blood pressure has been  affected by the toxin. Further stress on the heart should be avoided.