Are Hydrangeas Poisonous To Dogs. The hydrangea plant is found in many gardens and homes due to its gorgeous bright flowers. Dogs will become poisoned from eating any part of the hydrangea plant, says dr.

They come in a variety of colors and are beautiful. Hydrangeas are poisonous to cats and dogs, although it takes a lot for them to get sick. It is best to contact your veterinarian to seek their guidance.