Hedera azorica
Araliaceae
Azores Ivy; Azorean Ivy; Atlantic Ivy; Ivy; Hedera; Hedera azorica; Hedera spp.
Triterpenoid saponins, including hederasaponin C, hederasaponin B, hederasaponoside B, hederasaponoside C, and alpha-hederin; polyacetylene terpenoids, including falcarinol and didehydrofalcarinol; and other irritating compounds including rutin, caffeic acid, chlorogenic acid, and emetine.
Potent irritant; the cell sap may cause redness, itching, rash, blistering, or contact dermatitis when it comes into contact with living tissue. Symptoms of ingestion may include an immediate burning sensation in the mouth, throat, and oral mucosa; redness, blisters, rash, or visible irritation of the mouth; excessive drooling; obvious oral pain or discomfort; pawing at the mouth; hoarse or weak vocalization; excessive desire to drink; vomiting; diarrhea; abdominal pain; and gastrointestinal upset. In cases of extremely large ingestion, symptoms may include stupor, loss of coordination, low blood pressure, slow heart rate, convulsions, and coma. Old twentieth-century literature contains unconfirmed livestock-death reports, but modern documentation of fatal Hedera poisoning appears extremely limited.
Azores Ivy is a woody, evergreen, climbing or ground-creeping vine in the genus Hedera, within the family Araliaceae. Like other members within the genus, this plant has distinctive juvenile and adult life stages. In the juvenile stage, the plant will have characteristically lobed leaves and exhibit more herbaceous growth, often forming dense patches on the ground. The transition from juvenile to adult growth is generally triggered by the climbing of a host structure, such as a fence, wall, tree, or other vertical support. At that point, the plant develops woody vines, the leaves transition from lobed to unlobed, and the plant will eventually begin to produce umbels of small flowers on secondary branches.
Ivy is probably best known for its use in landscape decoration, and in 2010 it was estimated that approximately eight million potted ivy plants were sold in the United States alone. Ivy is not a newcomer to the field of decorative landscaping, having been used for this purpose for at least the last 300 years. During that time, a remarkable diversity of cultivars has been developed. Ivy, generically considered as Hedera spp., is native to western, central, and southern Europe, Macaronesia, northwestern Africa, and across central-southern Asia eastward to Japan and Taiwan.
All species within the genus should be considered toxic or irritating to some degree, as they can cause a negative physical reaction when ingested or when they make contact with unprotected skin. The primary toxins are triterpenoid saponins, including hederasaponin C, hederasaponin B, and hederasaponosides B and C, along with the polyacetylene terpenoid falcarinol. Falcarinol, a polyyne, is capable of inducing a relatively severe allergic or irritant contact dermatitis reaction in the skin of some individuals and animals. The reflex-expectorant effect of saponins has also helped the plant find use by some individuals in the holistic community for the treatment of dry cough.
Like many species of potentially harmful plants, the actual toxicity or lethality of ivy, regardless of species, seems to have been greatly exaggerated in some sources. In Poisonous Plants in Britain and Their Effects on Animals and Man (1984), authors Cooper, M. R. and Johnson, A. W. note:
Cattle that ingested large quantities of English ivy vine became ill and excitable, started staggering, and bellowed loudly. The odor of crushed ivy leaves was on the breath and in the milk. Recovery was quick and complete in three days.
Additionally, this author was unable to find a single confirmed fatality, human, animal, or otherwise, caused by the ingestion of any species in the genus Hedera. In fact, most reputable scientific and medical sources point out that the primary effect of ingestion seems to be limited to irritation of the digestive tract, generally manifesting as vomiting, diarrhea, coughing, and oral irritation. Hederin, one of the saponins isolated from the leaves of Hedera spp., is a strong and near-immediate irritant of the mucous membranes of the nose and throat. This tends to dissuade all but the most stubborn animals from consuming anything more than a negligible amount of the plant.
However, even with a small ingestion, there is still a risk of allergic and irritant contact dermatitis of the oral mucosa due to the polyacetylene compound falcarinol. The associated discomfort may include redness, swelling, irritation, and blisters in the mouth or throat. In a sensitive animal, this discomfort could make eating or drinking difficult for a period of time, potentially necessitating veterinary care or fluid support to maintain adequate hydration.
Immediate Response to Ingestion or Contact
- Remove the Source: Prevent further ingestion immediately by removing any remaining leaves, vines, stems, berries, or plant fragments from the pet’s reach.
- Remove and Flush Plant Material: If ingestion was recent and it is safe to do so, remove visible plant matter from the mouth and flush the mouth thoroughly with water to reduce lingering irritation from sap or plant fragments.
- Wash Exposed Skin: If the plant contacted the skin, lips, nose, gums, or other sensitive areas, gently wash the exposed area with mild pet-safe soap and water to reduce irritation from the plant sap.
- Do Not Ignore Oral Swelling: Redness, blistering, pawing at the mouth, difficulty swallowing, hoarse vocalization, facial swelling, or throat swelling should be treated as more serious signs because swelling in or near the mouth and throat can interfere with eating, drinking, or breathing.
- Contact Veterinary Help: Consult a veterinarian, emergency veterinary clinic, ASPCA Animal Poison Control, or Pet Poison Helpline if a large amount was ingested, if symptoms are present, if the pet is a cat, puppy, kitten, elderly animal, or medically fragile, or if there is any swelling of the face, mouth, tongue, or throat.
Inducing Vomiting and Decontamination
- Spontaneous Vomiting is Common: In many cases, the pet may vomit naturally after chewing or swallowing irritating, non-digestible plant material.
- Inducing Vomiting in Dogs Only: If exposure is recent and the dog is alert, breathing normally, and not showing weakness, collapse, tremors, severe oral swelling, or breathing difficulty, a veterinarian or animal poison-control professional may recommend inducing vomiting with fresh 3% hydrogen peroxide at the commonly referenced dose of 1 teaspoon per 10 pounds of body weight.
- Cat Warning: Hydrogen peroxide should not be used to induce vomiting in cats unless a veterinarian specifically directs it. Cats are more prone to irritation and complications from hydrogen peroxide, and home vomiting attempts may create more risk than benefit.
- Do Not Induce Vomiting in an Unstable Animal: Vomiting should not be attempted in any animal that is weak, collapsed, sedated, having trouble breathing, showing neurologic signs, unable to swallow normally, or showing significant mouth or throat swelling.
- Activated Charcoal: Activated medical charcoal may be useful in some ingestion cases, but it should be given only under veterinary or poison-control direction, especially if the animal is already vomiting, weak, or at risk of aspiration.
Symptomatic Care and Treatment
- Hydration: Ensure the pet receives adequate fluids to reduce the risk of dehydration from vomiting, diarrhea, or reduced willingness to drink because of oral irritation.
- Gastrointestinal Protection:
- Kapectolin: To alleviate gastrointestinal upset and diarrhea, Kapectolin may be given at a dose of 1 to 2 ml/kg four times daily to help coat and protect the stomach lining.
- Sucralfate: Sucralfate may be used for gastrointestinal irritation because it reacts with stomach acid to form a paste-like protective barrier between irritated tissue and stomach contents.
- Dogs greater than 60 lbs: 1g every 6 to 8 hours.
- Dogs less than 60 lbs: 0.5g every 6 to 8 hours.
- Cats: 0.25g every 8 to 12 hours.
- Veterinary Support: Animals that cannot keep water down, refuse food or water because of mouth pain, develop repeated vomiting or diarrhea, or show swelling of the mouth or throat may require veterinary monitoring, anti-nausea medication, gastrointestinal protectants, pain control, or fluid therapy.
Prognosis and Risks
- General Outlook: Life-threatening intoxication from ivy ingestion is exceedingly rare, and fatalities, while theoretically possible, are essentially unheard of in modern companion-animal documentation.
- Most Common Outcome: In most cases, symptoms are limited to irritation of the mouth and gastrointestinal tract, including drooling, vomiting, diarrhea, abdominal discomfort, and temporary refusal to eat or drink.
- Primary Concern: The most serious practical threat is not usually systemic poisoning, but the possibility of a severe irritant or allergic reaction to compounds such as falcarinol, especially if swelling or blistering affects the mouth, tongue, throat, or upper airway.
- Recovery: With appropriate symptomatic care, most animals are expected to make a full recovery within a few hours to a few days, depending on the amount ingested, the severity of oral irritation, hydration status, and the individual animal’s sensitivity.