Is Rue Toxic to Cats?
Also known as: Herb-of-Grace, Common Rue, Ruta graveolens · Ruta graveolens
What makes it toxic
Furanocoumarins (psoralen-type compounds) and bitter essential oils. Furanocoumarins are phototoxic — activated by UV light they damage skin cells — and the oils also irritate the mouth and digestive tract.
Warning signs to watch for
Drooling, vomiting, diarrhea and mouth redness after chewing. If sap gets on the fur and the cat goes into sunlight, reddened, blistered, painful skin appears on exposed areas within a day or two.
What to do if your cat eats it
Rinse the mouth, wash any sap off the coat with soap and water, and keep the cat indoors out of the sun. Call your vet the same day; skin blistering or repeated vomiting needs prompt professional care.
Common questions
Why does the plant cause sunburn-like burns?
The furanocoumarins in rue are phototoxic: after sap or crushed leaves touch the skin, UV light activates them and they burn the tissue, a reaction called phytophotodermatitis.
Is rue dangerous just growing in the garden?
Brushing against intact plants is usually harmless; bruising or cutting the leaves releases the oils. Keep cats away after pruning rue.
More plants checked for cats
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away. Checking what your pet can eat? Visit our sister site SafeOrToxic.