Is Lonicera japonica toxic to cats?

Mildly. The ASPCA lists lonicera japonica as mildly toxic to cats — a chewing cat typically gets mouth irritation, drooling, and vomiting rather than a medical emergency, but it is still best kept out of reach. Lonicera is not affirmatively listed as non-toxic by the ASPCA (its 'Honeysuckle Fuchsia' entry is the unrelated Fuchsia), and the berries of Japanese honeysuckle are reported to cause gastrointestinal upset in dogs, with the genus containing saponins and cyanogenic glycosides. Treat as mildly toxic, keep pets from the berries and foliage, and verify with a vet if eaten.

Lonicera is not affirmatively listed as non-toxic by the ASPCA (its 'Honeysuckle Fuchsia' entry is the unrelated Fuchsia), and the berries of Japanese honeysuckle are reported to cause gastrointestinal upset in dogs, with the genus containing saponins and cyanogenic glycosides. Treat as mildly toxic, keep pets from the berries and foliage, and verify with a vet if eaten. Signs usually appear soon after chewing rather than hours later — watch for drooling, pawing at the mouth, vomiting, loss of appetite, or unusual lethargy after your cat has had access to lonicera japonica.

Stay calm. Remove any plant from your cat's mouth and take the plant away. Note how much was eaten and when, and do not induce vomiting unless told to. Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 and follow their advice; a leaf or photo helps the vet treat it correctly.

The ASPCA classification Growli uses applies to both cats and dogs: Lonicera japonica is mildly toxic to dogs as well. See the full lonicera japonica pet-safety guide for both species.

For a similar look without the risk, see the best cats-safe plants list — every plant there is ASPCA non-toxic to cats and dogs.