Why it's dangerous
The plant contains steroidal saponins which act as irritants to the gastrointestinal system and can cause systemic neurological effects if ingested in large quantities.
Toxic compound: steroidal saponins
Good to know
While typically causing mild symptoms in dogs and cats, it is more dangerous to large grazing animals. Dilated pupils are specifically noted in cats.
Sources
This page is informational and is not veterinary advice. If your pet has been exposed to something risky, contact your vet or an animal poison control line right away.