Houseplants Toxic to Cats (Part 1)

1 Severely Toxic (Can Be Fatal)

Azalea/rhododendron (grayanotoxins): vomiting, diarrhea, weakness, heart failure.

Oleander (cardiac glycosides): vomiting, diarrhea, lethargy, irregular heartbeat, death.

Lily and day lily: fresh day lilies are human-toxic too and deadly to cats — vomiting, lethargy, kidney failure, death.

Chinaberry/neem (tetranortriterpenes): diarrhea, vomiting, drooling, depression, weakness, seizures; ripe berries are worst.

Iris (irisin): drooling, vomiting, drowsiness, diarrhea; concentrated in the rhizome.

2 Toxic (Mostly Gastrointestinal or Mild)

Borage (tannins, mucilage): vomiting, diarrhea, dermatitis.

Boxwood (alkaloids): vomiting, diarrhea.

Ivy (triterpene saponins): vomiting, belly pain, drooling, diarrhea; leaves worse than berries.

Coleus / painted nettle (essential oils): vomiting, diarrhea, depression, poor appetite,occasional bloody stools.

Butterfly jasmine (nightshade family): tremors, seizures, diarrhea, vomiting, drooling, drowsiness.

Carnation (irritant): mild vomiting/diarrhea, hives.

Catnip (nepetalactone): many cats love it, but it can cause vomiting and diarrhea; sedates some, stimulates others.

Chrysanthemum/daisy (pyrethrins and others): contact dermatitis, vomiting, diarrhea, anorexia, allergic reaction.

Kalanchoe (buffered toxins): vomiting, diarrhea, rare abnormal rhythm.

Jade plant (unknown toxin): vomiting, drunken gait, rare tremors.

Leek (N-propyl disulfide): vomiting, red-blood-cell breakdown (Heinz-body anemia), blood in urine, weakness, fast heart, panting.

Dragon tree / asparagus fern (saponins): vomiting, depression, drooling, dilated pupils.

Authorities such as the ASPCA list many more; this covers only common ones.