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Hydrangea Plants & Pets

By Tracy Morris ; Updated September 21, 2017
Because of their bright coloring, hydrangeas are grown as a specimen plant.

Although the hydrangea plant is native to Asia, the plant’s attractive shape and unusual habits make it popular throughout the world. Many varieties of hydrangea bushes produce clusters of flowers that might be warmer hues of red and pink or the cooler tones of lilac or blue depending on the amount of iron in the soil. But hydrangea bushes are toxic to pets such as dogs and cats. A gardener should use caution when bringing a hydrangea into a home with pets.


Hydrangeas contain a toxin that is similar to cyanide. If a pet ingests it, the toxin prevents the cells of an animal’s body from producing adenosine triphosphate (ATP). Various body systems, such as the central nervous and circulatory systems, rely on ATP for energy to sustain their functions. When denied ATP, these systems shut down.


A pet might encounter a hydrangea plant in a number of ways. Hydrangeas are a popular potted plant for Mother’s Day and Easter. A person gifted with a hydrangea in a pot might bring it into her home and leave it with the pets. Outdoors, a hydrangea is adaptable to a number of climates and conditions. It grows as well in poor soil as it does in well-amended soil, and it can adapt to full sun or partial shade.


Dogs are curious animals who like to explore and to hunt small game. This can bring them into contact with toxic plants such as hydrangea bushes that have been planted outdoors. A cat might be exposed to the dangers of hydrangea toxins more directly. Cats that are kept indoors have a tendency to chew on houseplants; the action is thought to provide fiber to help with digestion. But if a cat is chewing on a potted hydrangea, it can put the cat in contact with the plant’s toxins.


The best strategy to avoid accidental hydrangea poisoning is to limit your pet’s exposure to the plant. Don’t plant hydrangea bushes in areas that your pet frequents. If you must have a hydrangea bush, plant it outside of your dog’s fenced play area. If you allow your dog or cat to run free, fence your hydrangea plant so that they cannot go near it. If you have a potted hydrangea in the home, keep it in a room that your pet is not allowed to enter.


If your pet has been exposed to a hydrangea plant, take immediate action to minimize the poison's effects. First, try to induce vomiting to get the poison out of your pet’s stomach. Then feed your dog or cat a solution of activated charcoal and water, followed 30 minutes later by sodium sulphate. The activated charcoal binds to the toxins and prevents their absorption into your pet’s body, and the sodium sulphate coats the lining of the stomach and intestines. Next, ensure that the toxin passes out of your pet’s system as quickly as possible by feeding your pet a laxative. You should take your pet to a vet as quickly as you can. This procedure should only be done if your pet is responsive. If your pet is comatose or shows signs of nervous or circulatory system damage, see a vet immediately.


About the Author


Tracy Morris has been a freelance writer since 2000. She has published novels and numerous online articles. Her work has appeared in national magazines and newspapers including "Ferrets," "CatFancy," "Lexington Herald Leader" and "The Tulsa World." She holds a Bachelor of Arts in journalism from the University of Arkansas.