Foxglove

Foxglove, with its tiers of bell-shaped flowers, is popular as a garden plant and cut flower, but the whole plant — flowers, leaves, and stems — contains potent cardiac glycosides (digitalin). It's active enough to be the source of a human heart medication, so in cats even a small amount can lead to arrhythmia and death. Keep it out of any shared space.

The same class of cardiac toxin

Foxglove's cardiac glycosides are in the same class of heart toxin found in lily of the valley. Both plants directly disrupt the heart's contraction and rhythm with deadly effect, so if you encounter this group in a garden or arrangement, keep it firmly away from cats.

How cats get exposed

The flowers, leaves, and stems are toxic, and so is the vase water. A cat commonly chews a clump growing in the garden or touches a stem that arrived in a gift or arrangement. Even dried leaves retain toxicity.

How symptoms progress

After ingestion, signs usually begin within a few hours to a day with vomiting, drooling, and lethargy, then progress to heart-rhythm disturbances. Cardiac glycosides can slow or destabilize the heartbeat and, in severe cases, cause cardiac arrest — so trouble can be advancing in the heart while the cat still looks fine.

What to do right now

If there's any sign of chewing or swallowing, don't wait even without symptoms. Don't induce vomiting at home — get to a vet right away. Arrhythmias can worsen suddenly, so it's safest to be monitored at a clinic that can watch the heart with an ECG.

Safer flowers instead

If you need a flower for the garden or a vase, confirmed-safe roses or gerbera daisies are good choices.