Guest Post by Elena Edwards
Moo and I went on a camping trip with some friends in the Hood River area of Oregon over Memorial Day Weekend.
The area was super secluded, so I felt good about letting Moo off the leash to explore a little and have some fun herself (Moo’s not much of a wanderer, so she stays within sight).
The hills were painted with bright yellow Tansy Ragwort, and by the end of the trip Moo was literally covered with the yellow petals from the tansy after roaming through the brush. No harm done, right? Just good ol’ outdoor exploration.
You can imagine my shock when I was relaying this story to a friend a few days later, and they told me they thought Tansy was poisonous to dogs.
Luckily, Moo is totally fine. She’s not one to taste-test many of her findings in the outdoors, so she must not have ingested anything. Still, it was an eye opener that I really don’t know anything about harmful plants in the Pacific Northwest.
Thus, I decided to compile a list of 14 plants you might find on the trails this summer in Washington that are poisonous for dogs.
Toxic Urban Plants
English Holly is a tree or shrub that is primarily utilized within the Pacific Northwest as a decorative landscape plant.
However, English Holly is now considered a “weed of concern” in King County due to its encroachment into native forests.
It is considered mildly to moderately toxic to cats and dogs, so while you pup will most likely be good and sick if enough berries or leaves are ingested, life-threatening intoxication from this plant is very rare.
English Holly begins to bloom in the springtime, and will produce fruits in the fall (the leaves and berries are the poisonous parts of this tree if ingested).
Nausea, vomiting, drooling, diarrhea, drowsiness.
You’ve likely seen English Ivy growing within a garden, along a house, winding up a tree trunk, or spread throughout native habitats across the Pacific Northwest.
While it may be beautiful, it is considered a noxious weed in both Washington and Oregon, and its sale and cultivation is now banned due to its tendency to outgrow and choke out others plants.
Seriously, this stuff is all over the place. So much so that forests that are being invaded are now called “Ivy Forests”, which means you should keep your eyes peeled (and your dog on a leash) when hitting the trails.
All parts of English Ivy is poisonous to dogs if ingested (primarily the leaves though), and physical contact with the sap can create a rash on your pup.
Whether ingested or touched, your dog is likely to make a full recovery so long as your veterinarian is contacted as soon as symptoms begin to show.
Vomiting, diarrhea, spasms, staggering and paralysis
The Horse Chestnut is native to the mountainous-slopes of the eastern Balkan forests but has been introduced to North America.
Horse Chestnuts are pretty common in urban areas, so if you prefer taking your dog on hikes throughout town or in the city, it would be helpful to be able to differentiate this nut from the American Chestnut.
While ingesting of large amounts of the plant CAN result in death, the Horse Chestnut is infamous for it’s foul flavor, so it’s not super likely that any of our dogs would chow down enough material to really put their lives on the line.
More likely, a dog will show gastrointestinal symptoms anytime within 16 hours after eating any part of the plant.
Horse Chestnut trees are one of the first trees to leaf out as temperatures begin to warm, which was right around mid-May for Washingtonians this year.
Inflammation of mucous membranes, vomiting, thirst, weakness, muscular twitching, dilated pupils, stupor, stupor, paralysis, coma and death.
English Laurel, also called the Cherry Laurel, can be found in urban and rural areas throughout Washington, and is currently considered a noxious weed in the state.
While this plant is most commonly found in urban forests (it’s well established within Seattle), it has since spread and naturalized in more remote areas, so keep an eye out on the trails (primarily west of the Cascades, and within the Puget Sound area).
English laurel is considered highly toxic, and if your pup (or you) consumed any part of the leaves, fruits or seeds of this plant, it should be treated as an emergency.
Wilted, fallen leaves contain the largest amounts of the toxic compound but laurel berries can also be very toxic to dogs if swallowed in large quantities (especially if they are chewed).
These guys are around all year, so they’re a good plant to be able to identify if you’re a year-round adventurer.
Abdominal pain, abnormal heart rate, diarrhea, muscle weakness, drooling, temporary blindness, tremors, seizures, coma.
Ah alas, Washington’s beloved and beautiful state flower.
While I do love admiring these large, richly colorful flowers, they are unfortunately toxic, and much more so for dogs than humans.
Blooming in the spring, these beautiful, purple plants can be mildly to severely poisonous for dogs, depending on the amount ingested, as well as the hybrid of the plant (which comes in various colors).
It doesn’t take much to get a dog sick; in fact, if an animal ingests as little as 0.2% of their body weight in any part of the plant, they can be poisoned.
Rhododendrons can be found in the wild as well as within urban sprawl, so make sure to keep an eye out when walking past with you pup.
Burning of lips and mouth, salivation, nausea, severe vomiting, coma and death.
Toxic Rural Plants and Plants Found in the Forest
Wildflowers and forest plants in the Northwest are beautiful, often exhibiting bright colors.
While they might look harmless, you may be surprised to learn that several are highly toxic to dogs (and people).
Then there are some plants, like the salal bush and berries, that people think look toxic, or heard a rumor that they are, but actually aren’t (salal berries are not poisonous to dogs – in fact they are edible and quite tasty to some dogs and humans – and the leaves can be dried and used as medicinal tea).
To clear up some of the confusion, the most commonly encountered toxic plants found in the woods are listed below.
If you’ve lived or visited Washington in the summer, you’ve likely seen tansy ragwort (first picture in this article) and the common tansy. They grow about three feet tall and have golden, button-like clusters or flowers, and are actually quite pretty.
This weed is considered an invasive species to Washington State.
Originally used as an insect repellent (the fragrance of the weed helps repel ants and flies), Tansy has since naturalized throughout the United States, and can now be found along roadsides, streambanks, within pastures and in some forest areas.
All parts of the Tansy weed are considered highly toxic to dogs,
with the highest amount of alkaloids in flowers, then leaves, roots and stems. It even remains toxic when dry.
If consumed, call your vet immediately.
Rapid Pulse, dermatitis, head pressing, disorientation, stomach inflammation, convulsions, abortion, liver damage, kidney damage.
I’ll start by saying that the name “Death Camas” speaks for itself.
Death Camas are cream colored flowering plants that are native to the western United States.
The flowers of the plant grow in clusters that somewhat resemble onion bulbs. The big difference, of course, is that onions are edible and Death Camas can kill you and/or your dog, which is why it’s so important to be familiar with how poisonous plants in your area look.
Death Camas flower between April and July, and generally grow in dry meadows and hillsides, as well as montane forests and sagebrush slopes, so it’s not unlikely that they could be in the same neck of the woods that you may be hiking.
The entire plant—bulbs, leaves, flowers and pollen—can be poisonous to both humans and dogs if consumed.
Salivation, weakness, respiratory difficulty, paralysis, urination/defecation, nausea, convulsions, coma, and (if not treated) death.
Death Cap Mushroom
Of all the mushrooms that grow in the Pacific Northwest, the Death Cap Mushroom is a great one to be educated on for the sake of avoidance, for both you and your dog.
Similar in appearance to other edible mushrooms (Mother Nature has a sick sense of humor sometimes, doesn’t she?), the Death Cap Mushroom is one of the most poisonous mushrooms in the northern hemisphere.
They generally appear in summer and autumn months, and can be found in areas with oak, chestnut, and spruce trees, to name a few.
Severe abdominal pain, vomiting, diarrhea, gastrointestinal bleeding, coma, kidney failure, death.
Foxglove is a beautiful plant, with stacked bell-shaped lavender (they can also be white or yellow) flowers that grow tall and beautiful.
That being said, this plant contains a toxin found within its leaves, flowers and seeds that can be fatal to both humans and dogs if ingested (even the water that’s held within the vase part of the flower has been reported to cause toxicosis).
Foxglove blooms in early summer, and while they may be beautiful to look at on a sunny summer hike, I would recommend steering clear if you run into some.
There is no antidote for Foxglove poisoning, so for your pups sake, I wouldn’t risk it.
Contracted pupils, vomiting, diarrhea, cramps, severe headache, irregular heartbeat, labored breathing, convulsions, death.
Lily of the Valley
Lily of the Valley is a highly poisonous woodland plant that is found in the Northern Hemisphere, and blooms in late spring.
Ingestion of Lily of the Valley will result in similar symptoms to that of Foxglove, and should be treated aggressively.
Similar to Foxglove, these dainty white teacup-like flowers grow in large colonies and are beautiful and easy to appreciate.
Sadly, all parts of the plant are highly toxic—stems, leaves, flowers and berries–and should be avoided if possible.
Burning pain in the mouth and throat, salivation, nausea, vomiting, abdominal pain, headache, dilated pupils, slow and irregular heartbeat, coma and death.
Poison Hemlock/Water Hemlock
Poison Hemlock is a class B noxious weed within Washington, and can commonly be found along roadsides, in open fields, and basically in any natural, wild area.
It’s considered severely toxic to both humans and dogs, and if ingested symptoms will start to show anywhere from 20 minutes to three hours later.
All parts of the plant are toxic, and even the dead canes remain toxic for up to three years (yikes)!
Poison Hemlock begins to grow in late spring, and has a history of being confused with wild carrots and other plants within the parsley family.
Similar in appearance to the Poison Hemlock is Water Hemlock, one of the most poisonous plants in Washington state.
Water hemlock is a wetland plant, and can commonly be found growing in pastures or along the edge of water and irrigation canals.
It’s wise to be able to differentiate these two highly toxic plants, however both are highly toxic and should be avoided to the best of your ability.
Teeth grinding, muscle spasms, delirium, respiratory failure, death
The Bleeding Heart plant is a beautiful pink, heart shaped (go figure) plant that commonly adorns gardens along the Pacific Coast of North America. A non-domesticated version also grows wild in the forest.
They’re beautiful additions to any garden and are sure to be show-stoppers, but these guys are moderately toxic to dogs. Luckily, they’re easy to recognize due to their distinctive shape.
These plants prefer moist climates, making the Pacific Northwest a perfect home. Within the wild, they can usually be found growing in lowland coniferous forests, specifically within thickets, stream banks and and ravines.
It’s the foliage and the roots of the Bleeding Hearts that are poisonous to pets if consumed.
Loss of coordination, tremors, drooling, difficulty breathing, seizures, possible death
Larkspur is an eye-catching blue, purple or white flowering plant found in Northern America that is toxic to humans, livestock, and pets if consumed.
This flowering plant likes moisture, and is usually found in meadows along mountainsides, where snowfall can be found late into spring and early summer.
While all parts of the Larkspur are considered toxic, it’s the new-growth and seeds that contain the highest concentration of toxins, meaning they’re more likely to be harmful when they first bloom (spring/early summer) and become gradually less-so in late summer.
Drooling, abnormal heart rhythms, constipation, abdominal pain, paralysis, tremors, seizures, heart and lung failure, death.
Bracken Fern is native to Washington, and is considered toxic primarily to cattle and humans.
That being said, if your dog is exposed to this plant on a regular basis (whether it be in your backyard, or along an urban or trail you walk regularly), it could pose a threat to your pup.
Apparently, a dog would have to ingest this fern somewhat regularly for a few months time before serious results would occur, and same goes for you. Nothing to lose sleep over, but something good to be aware of if your dog likes to munch on plants in the yard.
I included the bracken fern solely because, hey, this is Washington and our climate is home to ferns abundant.
By all means, please do not let this list of plants serve as a deterrent to getting outdoors with your dog. Rather, I hope this has served to better educate you on poisonous plants to be aware of when hitting the trails, and given you confidence in your ability to know a dangerous plant from a harmless one.
No adventure comes without it’s risks, but in my experience, it really is always worth it.
About the Author
Hi, I’m Jessica. I’ve been studying the Dachshund breed since 2007, owned 3 of my own, and shared in the lives of thousands of others through their owner’s stories. When I’m not sharing what I know on this blog, you can find me hiking, camping, and traveling with my adventurous wiener dogs.