Are hydrangeas poisonous to dogs?

Updated 11/07/2023

Hydrangeas: popular garden shrubs found in strikingly cool shades of pink, blue and white - it’s no wonder they’re found in gardens around the world. Unfortunately, hydrangeas are poisonous to dogs, thanks to the cyanogenic glycosides - high concentrations of which are found especially in the flower and leaves. When eaten, it can cause a variety of nasty symptoms like sickness, diarrhea and lethargy.

Can dogs eat hydrangeas?

Under no circumstances should your pooch be chowing down on your outdoor plants - hydrangeas are toxic to dogs. If you’re a pet parent yourself, you'll know that pups and adult dogs are nothing if not curious creatures. This means that sadly, our canine friends can be prone to the odd nibble on our indoor and outdoor plants. The solution? Do your research and invest in pet-safe plants that won’t cause any adverse reactions, should your pup’s curiosity get the better of them.

Hydrangea poisoning

Symptoms

If you’re worried your pooch might have ingested some of your hydrangea plant, there are a few symptoms you can look out for that are likely to display within around half an hour of munching. Here are the symptoms common with hydrangea poisoning in dogs:

• Lethargy
• Vomiting 
• Diarrhea
• Depression
• Confusion

It is rare for animals to develop toxicosis or serious illness following the consumption of hydrangeas, gastrointestinal (tummy) upset is more common with symptoms generally being mild. Of course, if your pooch has gotten a hold of a lot of the plant, symptoms could become more severe and veterinary intervention would be required. Intervention is generally supportive to control symptoms.

Diagnosis 

If your pooch has been playing a little too closely to your hydrangea plant and you think they may have eaten part of it, call your veterinarian to discuss supportive care and if any treatment is needed. Symptoms will most likely come up within around half an hour after your pup got a little too curious and took a nibble. If you need to take your pooch to the veterinary clinic, you can take a sample of the plant you think your pet ingested to the vet (flowers, leaves and all) - this will help with an accurate diagnosis and treatment. Your veterinarian will perform a clinical exam, and blood tests or a hospital stay could be on the cards if your pet is very poorly from the plant's effects. 

Treatment

Like with other plant toxicity in your pooch, the treatment your vet administers will depend on how long ago it was ingested, along with other factors (like the age, health and size of your pet). Treatment you may expect at the vet includes induced vomiting. If your dog ate the plant within 30 mins - 1 hr, your veterinarian may deem decontamination / forced vomiting the right choice for your dog, as the detrimental effects of large volumes of the plant being ingested could be riskier than the act of causing vomiting. This treatment forcibly removes the plant from your pooches tummy and so prevents the risk of more serious poisoning symptoms. Intravenous fluids to prevent dehydration and support your pooch's symptoms whilst they recover may also be offered to your pooch.

Meet our veterinary expert, Lily

This article has been checked by veterinarian Lily Richards BSc (Hons) BVSc MRCVS. Lily qualified from Liverpool University in 2011 and spent 5 years as a veterinarian working in mixed animal practice. As Lily’s passion for exotics and exploring more complicated small animal medical cases developed, she stepped into small animal-only practice. By 2018 Lily was leading a busy branch of a large hospital practice with a fantastic team, enjoying working on both surgical and medical cases. Since falling poorly in 2021 Lily has found a new passion in medical writing. Sharing medical knowledge and writing for the public is a particular passion. 

Other plants that are poisonous for dogs

Many plants popular amongst us humans are in fact unsafe or even poisonous to our canine friends, so it’s vital to get in the know about which plants are safe and which aren’t. To get you started, below are a few plants to avoid if your house is home to furry friends.

• Geraniums
• Aloe vera
• Lilies
• Tulips