Are Hydrangeas Poisonous to Cats?

Hydrangeas are known for their stunning and colorful flowers, commonly found in gardens and as houseplants. They are also frequently used as floral decorations for special events. These plants have broad, flat green leaves and large flower clusters that come in various colors, including pink, red, blue, purple, and white. The hydrangea is also called the hortensia plant, hills of the snow, or seven bark, and shares the same toxin found in almonds, apple and pear seeds, and pits from fruits in the prunus species (cherry, peach, apricot, and plum).

All parts of the hydrangea plant are toxic, but the highest concentration is found in the leaves and flowers. While severe toxicity is very rare, mild poisoning is common and often leads to stomach upset in cats when they consume large amounts. The toxic substance in hydrangeas is called amygdalin, a cyanogenic glycoside that is also toxic in dogs, horses, and livestock. This toxin is activated when the plant is chewed, and it can trigger cyanide poisoning. Cyanide is a fast-acting toxin that enters the bloodstream and impairs the body’s ability to use oxygen properly. If you suspect your cat has ingested any amount of a hydrangea plant, they should be seen by their veterinarian as soon as possible or be taken to a veterinary emergency room.

How Many Hydrangeas Are Toxic to a Cat?

Unfortunately, it’s not known exactly how much of the hydrangea shrub or flowers your cat would need to eat to cause severe toxicity. Due to this unknown and the fast-acting toxicity that could occur after any ingestion, pet parents should bring their cat to the vet to ensure that they do not develop cyanide poisoning. Cats are more susceptible to hydrangea toxicity than dogs because of their small body size. Cyanide toxicity from the hydrangea plant is dose-dependent, meaning the more they eat, the higher the chance of developing clinical signs of poisoning.

Symptoms of Hydrangea Poisoning in Cats

Symptoms of hydrangea poisoning in cats include skin irritation on contact, nausea and drooling, vomiting, diarrhea (sometimes with blood), decreased appetite, lethargy, weakness and depression, and abdominal pain. In cases of cyanide poisoning, signs may include difficulty breathing, pale or blue gums, stiff limbs, seizures, elevated heart rate, and coma.

What Should I Do If My Cat Has Eaten a Hydrangea?

If you notice any of these symptoms or suspect your cat has ingested any part of the hydrangea plant, they should see a veterinarian as soon as possible. It’s always a good idea to bring part of the plant to the vet’s office with you so they can ensure proper identification, which will aid your veterinarian in treating your cat’s symptoms. If your cat has ingested a substantial amount of hydrangea, time is of the essence, as toxicity will continue to worsen with time and the continued absorption of the toxin. Do not induce vomiting at home for any possible poison ingestion without explicit direction from your vet to do so.

Treatment of Hydrangea Poisoning in Cats

Treatment for hydrangea toxicity in cats involves managing the symptoms, as there is no specific antidote. The approach to treatment depends on the severity of clinical signs and the amount of hydrangea ingested. For recent ingestions with cats exhibiting clinical signs but otherwise in good health, your veterinarian might induce vomiting to remove the source of poisoning and prevent further toxin from getting absorbed into the bloodstream. In severe cases, gastric lavage (stomach pumping) may be performed to physically eliminate plant material from the stomach. If your cat simply has stomach upset, your vet will likely prescribe antibiotics and anti-nausea medications to help with diarrhea and vomiting. Dehydration will be treated with fluid administration, either subcutaneously (under the skin) for mild cases or intravenously (IV) for more severe cases. In severe instances, your cat may need to be hospitalized for supportive care, including oxygen therapy if they have difficulty breathing. If your cat has an elevated heart rate, an EKG monitor may be used to ensure that their heart rhythm is normal, and medications can be given to help stabilize their heart rate.

FAQs

What are the symptoms of hydrangea poisoning in cats?

The symptoms of hydrangea poisoning in cats include skin irritation on contact, nausea and drooling, vomiting, diarrhea (sometimes with blood), decreased appetite, lethargy, weakness and depression, and abdominal pain. In cases of cyanide poisoning, signs may include difficulty breathing, pale or blue gums, stiff limbs, seizures, elevated heart rate, and coma.

How can I prevent hydrangea poisoning in cats?

If you have hydrangeas in the yard that your cat visits, you should figure out a way to prevent her from accessing the plants as much as possible. Through the garden, place shells, branches, and thorny vines which are not appealing for a dog or cat to step on. You can also try botanical oil sprays, motion-activated sprinklers, and ultrasonic deterrents to keep cats away from the plants.