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Is Periwinkle Toxic to Dogs?

☠️ ToxicSeverity: Moderate
✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit
⚠️ Educational info only. If your pet just chewed something and looks unwell, skip the reading and call your vet or Pet Poison Helpline (US): (855) 764-7661.
Yes, periwinkle is toxic to dogs. Eating the plant can cause vomiting, diarrhea, low blood pressure and, in larger amounts, tremors.

Also known as: Vinca, Madagascar Periwinkle, Catharanthus roseus · Catharanthus roseus

What makes it toxic

Vinca alkaloids (vincristine- and vinblastine-family compounds) throughout the plant. They interfere with cell division and nerve-muscle signaling.

Warning signs to watch for

Drooling, vomiting, diarrhea, weakness and depressed blood pressure within hours. Significant ingestion can add tremors, stumbling and seizures.

What to do if your dog eats it

Clear away the chewed plant and call your vet the same day with details. Any tremor, collapse or unusual weakness needs immediate emergency care.

Common questions

My dog grazed a bed of vincas on a walk — what should I do?

Call your vet with an estimate of how much foliage was eaten and watch for several hours. One small graze often means mild GI signs, but the alkaloids justify a call.

Are Vinca minor and Vinca major equally toxic?

Yes, the groundcover vincas carry the same alkaloid family as the annual bedding plant, so treat all of them as hazardous.

How long do symptoms take to appear?

Usually within a few hours. Because neurological signs can follow the stomach signs, keep monitoring for a full day even if the first hours look mild.

More plants checked for dogs

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.