Poison Ivy Poisoning in Dogs

Poison ivy, Toxicodendron radicans, is found in woody areas throughout most of North America and some parts of Asia. Despite its name, it doesn’t belong to the same family as other ivies and isn’t considered a true ivy. It is a well-known nuisance on hikes, since skin contact can cause dermatitis with an itchy, red rash developing a few days after exposure. An oil in the plant, called urushiol, is responsible for the histamine release that causes the rash. Unlike many plant toxins, urushiol is not a defense mechanism, but rather it assists the plant with water retention. It is extremely resilient and can be present in dead plant material for up to five years. Urushiol will also cling to clothing or fur unless it is actively washed off.

Poison ivy is not as toxic for dogs as it is for humans. Even among humans, allergic reactions can vary, with about 15-30% having no response at all. The rash is typically more severe with concentrated or repeated exposure. Dogs can respond with a similar rash as humans, but thick hair often protects the skin from exposure, even in urushiol sensitive dogs. Symptoms are most common in areas where dogs have thinner hair, like the stomach, nose, and groin, and hairless or short-haired dogs are more at risk. Symptoms are similar to humans, with an itchy rash developing at the point of contact, 3 days to a week after exposure. Severe cases can have fluid filled blisters that pop and spread the rash, increasing the chances of bacterial or fungal infection. Poison ivy isn’t especially toxic when eaten; in fact birds, bear and deer often consume the leaves and seeds for food. Dogs that ingest the plant may have gastrointestinal upset with symptoms of vomiting and diarrhea.

Even if your dog doesn’t have a reaction to poison ivy, it’s a good idea to avoid contact. Dogs that get the oil on their fur can transfer it to owners through petting or rubbing against the legs, and sensitive individuals can develop a reaction from secondary exposure. The plant has woody stems, and may grow as a low shrub or a vine. In is most commonly recognized by the well-known grouping of three almond-shaped leaves (called trifoliate), but it can also be seen as a thick hairy rope growing up the side of a tree. All parts of the plant contain urushiol oil.

Poison ivy poisoning is not as common in dogs as it is in humans. A dog’s fur will reduce the chance of skin exposure and many individuals appear not to be sensitive. However, some dogs experience the same symptoms as humans, with a red itchy rash developing at the point of contact. Ingestion of the plant also causes gastrointestinal upset.

These are the symptoms you may see if your dog is exposed to poison ivy.

• Red skin
• Swelling and itching
• Fluid-filled blisters or scabs
• Vomiting (ingestion)
• Diarrhea (ingestion)

Types

There are numerous varieties and sub-species of Toxicodendron radicans. The plant can be found in three different forms.

• Shrub – poison ivy grows as a shrub-like plant about 3 feet (1.2 meters) high with the typical trifoliate shaped leaves
• Trailing vine – poison ivy can form a trailing vine on the ground with leaf sprigs close to 10 inches (25 centimeters high)
• Climbing vine – poison ivy often climbs up the side of trees where it appears as a thick woody vine with horizontal hair-like protrusions on either side

• Dog walking through a poison ivy patch
• Dog rolling in a poison ivy patch
• Dog eating poison ivy
• Some breeds are more at risk

Diagnosis of poison ivy poisoning is usually based on symptoms and a history of exposure. Knowing that your dog was exposed to poison ivy can help correctly identify the condition. The rash will not appear until at least a few days later, and it may resemble other rashes and dermatitis. If your dog came in contact with poison ivy, you should check for symptoms regularly, especially where the hair is thin or short. The nose and muzzle are common areas of exposure as well as the belly, groin and inside of the legs. 

If your dog ingested poison ivy, it’s a good idea to call a veterinarian or a poison helpline, especially if a large amount was ingested. Be ready with a description of the plant, as well as your dog’s weight and how much you think was eaten. If you take your dog to see a veterinarian in person, bring a sample of the plant for correct identification. Handle it with gloves and transport it in a sealed plastic bag.

For immediate treatment, wash any area that came in contact with the plant thoroughly with soap and water. If urushiol oil is removed within a few hours, it will not cause symptoms, however, it’s impossible to know if the oil was successfully washed away until a few days later when the rash appears. Take the same precautions with yourself if you came in contact with the poison ivy, or with your dog after rolling in a poison ivy patch.

Mild cases of poison ivy poisoning will pass on their own. The veterinarian may prescribe topical ointments to reduce itching and make your dog more comfortable. Blisters and rashes that spread and become chronic should be covered to avoid infection and discourage your dog from scratching.

Systemic symptoms of fever, loss of appetite are possible, with very severe cases. If this is the case, you should definitely take your dog to see a veterinarian who can prescribe medication to treat the symptoms and ensure there isn’t a more serious infectious cause. Antibiotic or antifungal medication may be needed if infection is present.

With ingestion of poison ivy, symptoms of gastrointestinal upset are typically mild. Encourage your dog to drink fluids, and eat bland foods that won’t irritate the gastrointestinal tract further. If a large amount was ingested, veterinary treatment may be needed. Intravenous fluids and electrolytes can help prevent dehydration with severe vomiting and diarrhea.

Dogs usually recover from poison ivy poisoning without further problems. Recurrence can be an issue if there is a lot of poison ivy near your house, or where you walk your dog. Keep your dog on a leash around large poison ivy patches and discourage him from going near these areas on his own. Protective clothing, like dog sweaters, can be helpful if you take your dog on hikes.