Is Box (Boxwood) Poisonous? – Toxicity to Humans, Dogs, and Cats
Boxwood (Buxus spp.), commonly called box, is toxic to humans, dogs, cats, and horses. All parts of the plant are poisonous, with the leaves being the most commonly ingested. Boxwood is one of the most widely planted hedging and topiary shrubs in formal gardens, meaning exposure risk is more common than with most ornamental plants. If a person or animal has eaten any part of a boxwood plant, contact Poison Control or a vet without delay.
What Is Box or Boxwood?
Box and boxwood refer to plants in the genus Buxus, most commonly Buxus sempervirens (common boxwood). These slow-growing, dense evergreen shrubs are ubiquitous in formal garden design worldwide, used for hedges, topiary shapes, and border planting. The small, oval, dark green leaves are the part most likely to be encountered and ingested. The plant also produces small, inconspicuous flowers and small, round berries, all of which are toxic.
Their prevalence in public parks, formal gardens, and residential landscaping means children and pets encounter boxwood far more often than rarer poisonous ornamentals.
What Parts Are Toxic?
All parts of boxwood are toxic. The leaves hold a high concentration of alkaloids and are the most commonly ingested part, but the bark, stems, and berries are also toxic.
The active toxic compounds are steroidal alkaloids: buxine, cyclobuxine, and cycloprotobuxine. These affect the nervous system. Boxwood leaves have a noticeably bitter taste, which can naturally limit how much an animal or child eats before stopping. This should not be relied on as a safety mechanism, but it is why most exposures involve relatively small amounts.
Symptoms
Dogs and cats:
The ASPCA lists vomiting and diarrhea as the primary signs of boxwood ingestion in dogs and cats. These GI effects are the most common outcome from limited exposure. More significant ingestion can lead to lethargy and loss of coordination. Severe cases are possible, though the bitter taste often limits voluntary consumption.
Humans and children:
Ingestion causes nausea, vomiting, diarrhea, and abdominal pain. Larger doses can progress to dizziness and convulsions. Respiratory failure is possible in severe cases. Children are at particular risk because they may pick and chew the small, glossy leaves or berries without recognizing them as harmful. In horses, documented effects are more severe than in dogs or cats: colic, respiratory failure, and seizures have been reported by the ASPCA.
What to Do
- Remove any plant material from the mouth and rinse with water.
- Do not induce vomiting unless a medical professional specifically directs you to.
- For humans or children: call Poison Control at 1-800-222-1222 (US), available 24 hours a day, 7 days a week.
- For dogs or cats: call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435.
- Note which part of the plant was eaten and estimate how much. Bring a photo or sample if possible.
- Seek emergency care immediately if the person or animal shows signs of convulsions, difficulty breathing, or collapse.
Safe Handling
Boxwood does not cause significant skin irritation through touch. Wear gloves when pruning or handling large quantities of cuttings, primarily to prevent accidental hand-to-mouth transfer of plant material. Wash your hands after working with the plant.
If you have young children, be aware of boxwood in your garden, in neighbors’ gardens, and in public spaces you visit. Toddlers at the age of putting things in their mouths may pick up small leaves or berries. If boxwood hedging is directly accessible to young children at ground level, consider a low barrier or plant substitution.
Pets that chew plants should be supervised around boxwood or kept away from hedged areas where clippings accumulate on the ground.
Frequently Asked Questions
Is boxwood poisonous to touch? No. Skin contact with boxwood does not cause toxicity. Ingestion is the risk. Wash your hands after handling to prevent accidental transfer.
How toxic is boxwood to dogs? Toxic enough to require veterinary attention. Dogs that chew boxwood leaves typically show vomiting and diarrhea. The bitter taste usually limits how much they eat, but call a vet regardless of the amount. Do not wait for symptoms to develop.
Are boxwood berries more toxic than the leaves? Both are toxic. The leaves are more commonly ingested and hold a high concentration of alkaloids. The berries are also toxic and should be treated as a hazard for children and pets.
What is the difference between “box” and “boxwood”? They are the same plant. “Box” is the common British English name. “Boxwood” is more common in American English. Both refer to Buxus species, and the toxicity is the same.
Can boxwood kill a pet? Severe poisoning is possible, though the bitter taste limits ingestion in most cases. Do not wait to see how symptoms develop. Call a vet as soon as you know or suspect your pet has eaten boxwood.