Ready to plant an outdoor garden? Before you grab your garden trowel and dig in, read what we’ve dug up on outdoor plants that are dangerous to dogs.
We’ve uncovered some of the most common plants that are popular choices for many gardeners, yet are potentially poisonous for our canine companions. In this article, you’ll learn:
- the top 10 common garden plants that are dangerous to dogs
- the signs of plant poisoning in dogs
- what to do if your dog does ingest a toxic plant
- where to find information about garden plants that are safe for dogs
Top 10 garden plants that are dangerous for dogs
To help you plan ahead and keep your dog safe, here is a list of 10 common garden plants that are dangerous to dogs. (Plants are listed in alphabetical order.)
1. Autumn Crocus: highly poisonous to dogs
There are many species of crocus, but the most dangerous species for dogs is the Autumn Crocus, Colchicum autumnale. The plant is originally from the Mediterranean and Asia. The whole plant is poisonous to dogs, but the highest concentration of the toxin is found in the bulbs. Colchicine, the toxic agent in the plant, is highly toxic and can cause death with as little as 0.8 milligrams per kilogram.
Symptoms caused by colchicine include:
- a burning sensation in the dog’s mouth and throat
- vomiting and/or diarrhea that often has blood
- liver and kidney failure
- heart arrhythmias
- and sudden death
Toxin Trivia: Colchicine, the toxic agent in the autumn crocus, has been used for centuries to treat gout in humans.
2. Azalea: a popular plant that is highly poisonous to dogs
There are over 250 species of Azalea (Rhododendron spp.) found throughout North America. Despite their beautiful showy flowers that can bloom any time from the spring through the fall, azaleas are a popular outdoor plant that is highly toxic to dogs. Symptoms can occur when a dog has eaten as little as 0.2% of his or her body weight. Grayanotoxins in azaleas primarily affect the dog’s heart and intestinal tract.
Symptoms of poisoning in dogs from this plant include:
- diarrhea with or without blood
- changes in heart rate
- low blood pressure
- and even death
Toxin Trivia: Bees that feed on A
3. Chrysanthemum: less toxic, but still a plant that is poisonous to dogs
Chrysanthemum (Chrysanthemum spp.) are beautiful flowering plants that are originally native to Asia. The toxic components of the plants include sesquiterpene, lactones, and pyrethrins. The good news is that chrysanthemums have a relatively low risk of fatal toxicity compared with other plants on this list.
Signs of toxicity in dogs can include:
- incoordination and imbalance may occur with extreme ingestion of the toxic components
Toxin Trivia: Pyrethrins are used as flea preventatives and derived from the flowers of the plant, while pyrethroids are the synthetic version of the compound naturally found in the plants. Dogs are more tolerant of pyrethrins than cats, and pyrethrin flea and tick preventatives can be used safely in dogs.
4. Daffodil: mild to moderately poisonous to dogs
Daffodils are probably one of the most recognizable signs that spring is on the way. Most of the toxic components, such as lycorine, other alkaloids, and calcium oxalates are found in the bulb of the plant.
Signs of toxicity in dogs include:
- oral irritation and drooling
- low blood pressure
- low heart rate
Daffodil toxicity is generally mild to moderate compared with other species on this list of plants that are toxic
Toxin Trivia: Daffodils were first cultivated by the ancient Romans.
5. English Ivy: mild to moderately poisonous to dogs
English Ivy (Hedera helix) is sometimes kept as a houseplant, but it is probably most recognized for how it climbs up the sides of older buildings on colleges and historic homes. The toxic components of the plant, triterpenoid saponins, cause irritation of the mouth and intestinal tract.
Ivy has relatively mild to moderate effects compared with other toxic plants in this list, and the leaves contain more of the toxins than the berries.
Signs of toxicity in dogs can include:
- oral irritation
Toxin Trivia: Because English Ivy is an invasive species in the United States, sale of the plant is banned in Oregon.
6. Lily of the Valley: a delicate plant that packs a dangerous punch for dogs (moderate to severe toxicity)
Lily of the Valley (Convallaria majalis) is well known for its delicate white flowers. Despite their seemingly innocent appearance, they contain deadly cardiac glycosides that work by affecting the electrical activity of the dog’s heart. This can lead to signs of poisoning in dogs such as:
- a slowed heart rate
- low blood pressure
The toxins in this plant are very potent and can be deadly for dogs.
Toxin Trivia: Lily of the valley is the national flower of Finland.
7. Oleander: a beautiful plant that is moderate to severely poisonous to dogs
Oleander (Nerium oleander) was originally native to Northwest Africa and Southeast
Signs of oleander plant toxicity in dogs include:
Toxin Trivia: The toxic dose of oleander in horses and cows is only 0.005% of their body weight.
8. Sago Palm: highly poisonous to dogs
Sago Palms (Cycas revoluta) contain a highly toxic agent known as cycasin. The molecule is found in the highest concentration in the seeds, but is found throughout the plant too. Cycasin is broken down in the gut and causes significant damage to the liver. Signs of toxicity such as vomiting, diarrhea, and drooling can be seen anywhere from 15 minutes to a couple of hours after ingestion. Liver failure can occur two to three days after ingestion. The liver failure may appear as vomiting, diarrhea, yellow appearance to the skin, fluid build up in the abdomen and neurological signs such as weakness and imbalance. Sago palms are a common garden plant that is highly toxic to dogs.
Toxin Trivia: Although the Sago Palm superficially looks like a palm tree, it is not actually in the palm family. Palm trees are in the family Arecaceae, while sago palms are in the family Cycadaceae.
9. Tulip and Hyacinth: mild to moderately poisonous to dogs
Tulips (Tulipa spp.) and Hyacinth (Hyacinthus spp.) are two popular bulb species that both contain a similar toxin. Alkaloids are located in the highest concentration in the bulbs.
Typical signs of toxicity include:
- oral irritation
- increased heart rate and respiratory rate, trouble breathing (if large quantities are eaten)
Toxi Trivia: Hyacinth
10. Yew: highly poisonous to dogs
There are many species of Yew, but the most toxic species are Japanese yew (Taxus cuspidate), English yew (Taxus baccata), and Chinese yew (Taxus
It only takes a small amount of exposure, such as a dog chewing on a branch, to cause signs of poisoning including:
- dilated pupils
- trouble breathing
- sudden changes in heart rate and blood pressure
- sudden death
Thankfully, poisoning in dogs is rare due to the bitter nature of yew.
Toxin Trivia: Taxol (paclitaxel), a chemotherapeutic medication used to treat cancer in humans, was originally derived from the Pacific Yew tree.
A caution for our feline friends: Lilies are highly poisonous to cats
Even though dogs are the focus of this article, we cannot neglect our feline friends. Lilies are highly toxic to cats, to the point where even grooming pollen from the fur or drinking water out of a vase that holds lilies can cause kidney failure. Signs typically occur within six to 12 hours after exposure and include lethargy, decreased appetite, vomiting, diarrhea, changes in urination (either increased urination or no urine production), kidney failure, and some cats may show signs such as imbalance, head pressing, and seizures.
Yikes! I think my dog (or cat) ate a plant that may be poisonous. What do I do?
- Call your veterinarian and/or the ASPCA Poison Control at 1-888-426-4435 (consult fee applies), or the Pet Poison Helpline at 1-855-764-7661 (consult fee applies).
- Take pictures of the plant and the label on the plant’s container (if still in its original container) to help with identification.
- Act quickly. For most toxicity cases, it is better to seek help and start treatment early instead of waiting to see what happens.
Top 10 Toxic Garden Plants Infographic
I’m concerned about what to plant in my garden. Which plants are safe for dogs?
If you are debating which plants are safe for your garden, the ASPCA Poison Control has a helpful website for identifying a wide variety of toxic and nontoxic plants. For an entire list of plants that are dangerous to dogs as well as a list of plants that are safe for dogs, see the ASPCA’s article: Toxic and Nontoxic Plants.
Helping you help your dog
Finally, as summer heats up, please keep your dog safe from another outdoor danger:
Protecting our dogs from danger begins both inside our homes (be aware of the poisons in your pantry such as xylitol, chocolate, and even human toothpaste) as well as outside. By educating and informing yourself, you can give your dog the happiest, healthiest, longest life possible.
What questions do you have about garden plants that are dangerous to dogs?
I’d love to hear. Please comment below.
- “10 Common Poisonous Plants for Dogs.” PetMD, 18 Mar. 2019, www.petmd.com/dog/slideshows/emergency/poisonous-plants-to-dogs.
- “17 Plants Poisonous to Pets.” ASPCA Professional, 4 Dec. 2017, www.aspcapro.org/resource/shelter-health-poison-control/17-plants-poisonous-pets.
- Knight, Tony. “Guide to Poisonous Plants.” Guide to Poisonous Plants – College of Veterinary Medicine and Biomedical Sciences – Colorado State University, 2019, https://csuvth.colostate.edu/poisonous_plants/.
- Osweiler, Gary D, et al., editors. Small Animal Toxicology. Wiley-Blackwell, 2011.
- “Science and Nature Team Up Against Breast and Ovarian Cancers.” National Cancer Institute, 31 Mar. 2015, www.cancer.gov/research/progress/discovery/taxol.
- “Spring Toxins | AKC Reunite.” Lost Pet Recovery Service, 2019, www.akcreunite.org/springtoxins/.
- “Top 10 Plants Poisonous to Pets.” Pet Poison Helpline, www.petpoisonhelpline.com/pet-owners/basics/top-10-plants-poisonous-to-pets/.