Plants Poisonous to Dogs

We love our trees, shrubs, flowers, and houseplants for good reason. They reduce our stress levels, improve our health, increase our connections to nature, and bring us hours of aesthetic appreciation. Unfortunately, some of our favorite plants can be dangerous to dogs, causing gastrointestinal distress, vision problems, confusion, organ failure, and even death.

What dogs are at risk of poisonous plants?

Any dog can be drawn to a tree, flower, or houseplant that is potentially toxic, but at the top of the risk list are puppies who explore the world by sniffing, tasting, picking up, or swallowing whatever they encounter. Next are active dogs of any age, especially those who love to fetch sticks, dig in the dirt, or search everywhere for something edible.

What are the signs of plant poisoning in dogs?

Symptoms vary by plant, but in general, a plant that causes contact dermatitis will generate painful sores, especially in the mouth and mucous membranes. More serious are the symptoms of poisoning from an ingested plant, which include drowsiness, vomiting, diarrhea, a lack of appetite, weakness, staggering, a loss of balance, and in some cases convulsions or coma. Plant poisoning requires rapid medical treatment.

Plants poisonous to dogs

If you study reports about plants that are toxic to dogs, the lists can seem endless. Even benign plants, like the beneficial herb chamomile or the stems and leaves of tomato, pepper, eggplant, or potato plants, can be harmful to dogs if they swallow enough. However, the following plants are of greater concern because they can cause a serious reaction, even if only small amounts are consumed:

• Oleander branches, leaves, and flowers can cause liver failure and a fatal decrease in heart rate.
• Azaleas and rhododendrons can cause vomiting, diarrhea, vision problems, and even coma or death.
• The sago palm, a popular landscaping and house plant, contains a toxin called cycasin, which is so harmful that any part of the plant, including a single seed, can cause death.
• The autumn crocus contains colchicine, which causes gastrointestinal bleeding, severe vomiting, kidney and liver damage, and respiratory failure. Symptoms may not develop for several days, so don’t delay veterinary attention if your dog swallows any part of this plant.
• Daffodil, tulip, hyacinth, gladiolus, and amaryllis bulbs, flowers, and leaves can cause abdominal pain, vomiting, excessive drooling, and diarrhea. In severe cases, these bulbs cause cardiac arrhythmias (irregular heartbeats), respiratory problems, lethargy, and convulsions.
• Mushrooms are a seasonal problem in some areas. While most of the world’s 10,000 mushroom species are harmless to dogs, some wild mushrooms can be fatal, even in small amounts. Clinical signs of mushroom toxicity include excessive salivation, vomiting, diarrhea, liver failure, tremors, and seizures.
• Holly leaves (American, English, Japanese, and Christmas varieties) can cause vomiting, diarrhea, drooling, lip smacking, head shaking, a swollen mouth and tongue, and difficulty breathing.
• Lily of the valley and gloriosa or flame lily can lead to cardiac arrythmias, decreased heart rates, and seizures. Daylilies, which are extremely toxic to cats (as are all lilies), cause only gastrointestinal upsets in dogs.
• Elephant’s ear, golden pothos (devil’s ivy), English ivy, philodendron, calla lily, peace lily, and dumb cane contain insoluble calcium oxalate crystals that resemble sharp glass and cause oral irritation, mouth swelling, respiratory problems, skin irritation, vomiting, and coughing,
• Other common plants that cause serious problems for dogs who ingest them include milkweed, castor bean, foxglove, and cyclamen.

Many more plants are listed as dangerous by various sources, though some warnings apply only to other species or include only minor effects. When in doubt, look for information from reliable sources, such as the poison control centers listed below.

What to do if your dog swallows a dangerous plant

• Check your dog’s breathing and overall appearance so you can provide an accurate description of your dog’s symptoms, including his weight.
• Take notes about when and where the exposure occurred or when you noticed symptoms so you can describe the symptoms’ progression.
• If you suspect a specific plant but don’t recognize it, take its photo or collect a sample of the plant to help with identification.
• Save a sample of the dog’s vomit, if any.
• Do not give your dog any home remedies such as milk, salt, or oil.
• Do not induce vomiting without talking to your veterinarian or a poison control center. In some cases, vomiting may be detrimental.

Depending on your dog’s condition and the plant she ingested, your veterinarian might administer a liquid suspension of activated charcoal, which can absorb certain toxins. If appropriate, hydrogen peroxide or a similar substance can cause vomiting to help remove plant material from the dog’s stomach.

Intravenous fluids and medications may be necessary for more serious reactions. Techniques such as total plasma exchange and plasma absorption (using a specialized machine to remove toxins from the blood) may prevent a fatal poisoning, such as from a toxic mushroom, if performed in time.

Prevention is the best approach

It’s good to be organized, well informed, and ready to respond to emergencies, but preventing them in the first place is the best approach. Study the plants in your house and yard so you know which are potentially dangerous.

Move toxic houseplants out of your dog’s reach. If a plant is irresistible to your dog, use a pet gate or other obstacle to keep her from reaching it. If that doesn’t work, consider rehoming the plant.

Use positive reinforcement to reward your puppy for staying away from problem plants by focusing on his name and rewarding him for coming when called. The safest place for puppies and adolescent dogs when no one is home where there are potentially toxic house plants is in a crate.

Make house and garden plants unattractive to dogs by spraying them with lemon juice diluted with an equal amount of water. Reinforce the scent by placing lemon slices in plant pots or on the ground outdoors. Bitter Apple, Bitter Yuck, chili pepper sauce diluted with water, and other sprays that discourage chewing can be sprayed on and around harmful plants. Some trainers recommend sprinkling cayenne pepper powder around poisonous plants.

Chicken wire laid on the ground discourages digging. It can also be used to fence off sections of your yard. But the safest thing to do if you have a puppy or a dog who likes to dig or chew on plants is to remove toxic plants from your yard. And if you’re planning a garden, beginning a landscaping project, or deciding what plants to grow in your house, eliminate the risk and choose nontoxic dog-friendly species.