Plants Toxic to Dogs: A Pacific Northwest Field Guide

The plants most likely to seriously poison a dog in a Pacific Northwest house and yard are yew, rhododendron and azalea, Japanese pieris, cherry laurel, foxglove, lily of the valley, daffodil bulbs and sago palm, along with wild Amanita mushrooms after the fall rains. Most popular houseplants, including pothos, philodendron and peace lily, cause a burning mouth and vomiting rather than real poisoning. If your puppy eats something, call a pet poison line before you do anything else.

We checked every plant here against the ASPCA's plant database or Pet Poison Helpline, and both where both cover it, with Cornell and Washington State University where they add something for our region. Plants we could not verify for dogs are left out rather than guessed at. Foods have their own page, toxic foods and nine rules for feeding, and the room-by-room walk is in the new puppy checklist. This page is everything else a puppy can find.

If Your Puppy Ate Something

This comes first because it is what you will need in a hurry. Read it now, save the numbers, and print the card for the fridge.

Is This Plant Toxic to Dogs? Look It Up

Fifty-nine plants a puppy is likely to meet in a Pacific Northwest home, garden or trail. We sorted them into four levels by what the sources describe, so the list says how worried to be.

• Dangerous The sources describe heart effects, organ damage, seizures or death.
• Harmful More than an upset stomach, but rarely life-threatening. Still call.
• Mild A burning mouth, drooling or a stomach upset. Still call, and let the poison line decide.
• Non-toxic Listed by the ASPCA as non-toxic to dogs. No poisoning, though a big mouthful can still cause vomiting.

Which plants are toxic to puppies?

The same ones as for adult dogs, with more risk, because a puppy chews everything and weighs less. Tick Have beside each plant in your home and the page builds your own list of what to remove, what to move, and what is fine. We do not save your ticks; they live in this page's address, so you can bookmark the page or send it to someone. A plant missing from this list is not a safe plant. The ASPCA database covers hundreds more.

The Plants to Worry About in a Pacific Northwest Yard

Most lists of toxic plants are written for the whole country, so they lead with oleander and sago palm. Around Lynden, the plants that matter most are the ones in nearly every yard and hedge.

Yew. The dark-needled hedge in front of so many houses here, and a native tree in our forests. Every part except the red flesh around the seed is toxic, the seed most of all, and the effect is on the heart: Pet Poison Helpline and the ASPCA both describe sudden death from heart failure.² Bag the trimmings after you cut a yew hedge. Washington State University reports livestock poisoned after being fed yew trimmings.⁴

Rhododendron, azalea and Japanese pieris. These three share a toxin that acts on the heart and nervous system, and Pet Poison Helpline notes that signs can follow a few leaves or flowers.² They are evergreen, so the leaves are there all year.

Cherry laurel. The fast-growing laurel hedge. Its leaves, stems and seeds contain compounds that release cyanide, and the ASPCA lists breathing difficulty and shock.^{1, 2}

Foxglove. WSU describes it as a common garden flower and sometimes a wild escapee, and lists it among the region's poisonous plants.⁴ It contains cardiac glycosides, the same compounds as the heart drug digoxin.¹

Spring bulbs. Daffodils are the bulb on our list rated Dangerous, tulips and hyacinths Harmful, and the ASPCA notes that the bulb is the most poisonous part.¹ Cornell notes that bulbs planted with bone meal can draw dogs to dig them up,³ and a Lagotto needs very little encouragement to dig. Plant bulbs where the puppy cannot reach, and keep the bag in the garage closed.

In the wild. WSU lists poison hemlock as a common weed here, and water hemlock grows in wet ditches and along streams.⁴ Both are dangerous. A puppy on a leash on a walk is a puppy you can steer away from both.

Houseplants: What "Toxic" Usually Means, and Which Are Safe

Most houseplants on "toxic to dogs" lists, including pothos, philodendron, peace lily, monstera and dieffenbachia, contain microscopic needle-shaped crystals of calcium oxalate. Chewing a leaf drives them into the mouth, which burns at once. The usual result is drooling, pawing at the mouth and vomiting.² It is unpleasant and rarely dangerous, though in rare cases the throat swells enough to affect breathing. Call, and let the poison line decide it is mild.

The dangerous houseplants are fewer: sago palm above all, which the ASPCA says is fatal in up to half of ingestion cases,⁵ and to a lesser degree cyclamen and kalanchoe.

Which houseplants are safe for dogs?

The ASPCA lists these common houseplants as non-toxic to dogs: spider plant, Boston fern, calathea (prayer plant), parlor palm, areca palm, African violet, Christmas cactus and peperomia.¹ Non-toxic means no poisoning, not that a puppy can eat the whole pot. A big mouthful of anything, and the potting soil with it, can still upset a stomach.

Are lilies toxic to dogs?

Easter lilies (a true lily) and daylilies (not a true lily) are both listed by the ASPCA as non-toxic to dogs. Both are among the most dangerous plants there are for cats: any part, the pollen or even the water from the vase can cause kidney failure.¹ If you have a cat, keep them out of the house. Lily of the valley and peace lily are not true lilies either, and both affect dogs; they are in the list above.

Hazards Through the Year in the Pacific Northwest

Some of the risk is seasonal, and it follows our weather. Dangerous plants such as yew and rhododendron are there all year, so they are not on the wheel. Pick a month and the wheel shows what to watch for then. It opens on the current month. Where a public-health source gives a season, we cite it; where none does, the timing is what we see around Lynden, and we say so.

Mushrooms in the Yard: The Pacific Northwest Problem

Wet weather brings mushrooms up in lawns and under hedges, sometimes overnight, and among them in this region is the death cap, Amanita phalloides, which King County public health warns about every fall.⁶ Its toxins attack the liver, and the first signs do not appear until six to twenty-four hours after it is eaten. Two relatives, the fly agaric and the panther cap, act on the nervous system within half an hour to two hours.⁷

Most mushrooms are harmless, but you cannot tell which by looking, and Pet Poison Helpline's advice is to treat any wild mushroom a dog eats as poisonous until it is identified.⁸ Prevention is a walk around the yard after rain with a bag in your hand.

What to do if your dog ate a mushroom

Call first, then do these three things on the way, as Pet Poison Helpline and the North American Mycological Association describe.^{8, 9}

The Garage, the Yard and the Bathroom Cabinet

Plants are not where most poisonings come from. Plants and fungi together made up 7.5 percent of the calls to the ASPCA's poison center in 2025, behind medicines, food and several other categories.¹⁵ Pet Poison Helpline's 2025 list of the ten most common dog poisonings has no houseplants or garden plants on it: it is chocolate, grapes and raisins, bromethalin rat bait, xylitol, the onion family, ibuprofen, vitamin D3, cannabis, anticoagulant rat bait and acetaminophen.¹⁴ Foods are covered on our toxic foods page. The rest is below, by where you will find it.

Lakes, Ponds and Blue-Green Algae

The Lagotto is a water dog, and given the chance a young one will swim in anything. In warm weather, some lakes and ponds grow toxic blooms of cyanobacteria, often called blue-green algae. The Washington State Department of Health describes them as most common in summer and fall, though they can form at any time, and says they often look like green paint floating on the water, or a bluish, brownish or reddish scum.¹⁰ A dog can be poisoned by drinking the water. The nerve toxins can cause weakness, staggering, trouble breathing and convulsions within fifteen to twenty minutes.¹⁰

Keep your puppy out of any water that is green, scummy or posted with a warning, and call your vet at once if it becomes ill after a swim. Your county health department posts lake warnings.

Teaching a Puppy to Give It Up

Prevention is mostly management in the first months: gates, closed doors, a puppy that goes into the yard on a leash until you have walked it, and nothing on the floor you would not want eaten. Training does the rest, slowly.

Trade, do not chase. When a puppy picks something up, chasing it turns the object into a prize and teaches it to swallow fast. Instead, offer something better, a piece of cheese or a favorite toy, and praise the moment the mouth opens. Practice trades with toys every day, when nothing is at stake, so the exchange is automatic when it matters.

Teach "leave it" with food in your hand. Close your hand over a treat. When the puppy stops nosing it, even for a second, mark it and reward from the other hand. Build the duration slowly, then move to a treat on the floor under your foot. In our experience a Lagotto learns this quickly and holds it best when it is always paid.

Keep the methods gentle. A sensitive breed that is shouted at for picking things up learns to hide what it has found, and to eat it faster. Our training resources list the trainers and books we trust.

A Yard You Have Walked

None of this needs a bare yard or an empty house. It needs one walk around both at puppy height, a few plants moved or removed, the garage shelf put out of reach, and the two numbers in your phone. After that, the rest is a habit: a look at the lawn after rain, a closed bag of bulbs, a puppy that trades what it finds. If you are still deciding on a Lagotto, our puppies page explains how our program works.