Is Autumn Crocus Toxic to Dogs?

Autumn Crocus (Colchicum autumnale) is severely toxic to dogs, cats, and horses according to the ASPCA Animal Poison Control Center plant database. The toxic compound, colchicine, is present in every part of the plant (bulb, leaves, flowers) and is the same compound used in human medicine for gout, where it has a narrow therapeutic margin. The Merck Veterinary Manual lists Autumn Crocus alongside Lily of the Valley and Foxglove as one of the most dangerous garden bulbs.

Symptoms of Autumn Crocus ingestion in dogs can be delayed by 2-3 days, which makes the plant especially dangerous. Initial symptoms: vomiting, bloody diarrhea, drooling. Later symptoms: bone marrow suppression, organ failure, and shock. The fatality rate is high, and there is no specific antidote. If your dog has any exposure, call the ASPCA at (888) 426-4435 even if the dog seems fine right away. Delayed onset is the rule, not the exception.

Autumn Crocus is not actually a crocus despite the name. True crocus (Crocus species, the common spring bulb) is in a different family and is far less toxic. Autumn Crocus is sometimes confused with the safer fall-blooming Saffron Crocus (Crocus sativus). Read the scientific name on the bulb package; Colchicum is the genus to avoid.

Safe native alternative: Rain Lily (Zephyranthes drummondii). Pops up after summer rains with white star-shaped flowers, native to Texas prairies, and is not on the ASPCA toxic plant list. Low maintenance, Zones 7-10. If you have Autumn Crocus bulbs in a yard with pets, dig them up. Dispose of the bulbs in the trash, not the compost; bulbs remain toxic for years.