Autumn crocus (Colchicum autumnale) in Pets

Autumn crocus contains colchicine and can cause multi-organ failure; spring crocus usually does not. Learn how to tell them apart, the delayed signs and what to do now.

What It Is

Autumn crocus, also called meadow saffron, flowers in autumn from an underground corm. It contains colchicine, which stops cells from dividing. Tissues that renew quickly, such as the gut lining and bone marrow, fail first. It is not the same as spring-flowering crocuses (Crocus species), which usually cause only mild stomach upset.

Where Pets Come Across It

Gardens and lawns in late summer and autumn, wild meadows in Europe, and dried flowers or corms sold for planting.

Which Animals Are Affected

Dogs, cats, horses and livestock. All are susceptible to colchicine.

Published Toxic Dose

No owner-usable mg/kg threshold is published for pets; colchicine content varies by plant part. Pet Poison Helpline states that ingestion of fresh or dried plant causes severe poisoning with organ failure, shock, blood cell abnormalities and death. The calculator does not grade colchicine exposure by dose.

Signs and How Soon They Appear

Signs may be delayed by hours: vomiting, bloody diarrhoea, abdominal pain and dehydration first, then shock, kidney and liver damage, breathing problems and a drop in white blood cells several days later.

What to Do Right Now

Call your vet or a poison line now, even without signs, and confirm whether the plant was autumn crocus or a spring crocus. Bring a sample or photo. Do not induce vomiting at home.

Autumn crocus, saffron crocus and look-alikes

Three plants are often confused. Autumn crocus (Colchicum autumnale) produces pink-purple goblet flowers in late summer or autumn without leaves, then large, broad, glossy leaves the following spring; it has six stamens. Saffron crocus (Crocus sativus) also flowers in autumn but has narrow grass-like leaves with a pale central stripe and only three stamens, with long red stigmas. Spring crocuses (Crocus species) flower in early spring with grass-like leaves and usually cause only mild stomach upset. The broad spring leaves of Colchicum are sometimes mistaken for wild garlic or other edible greens. Mark autumn crocus clumps in your garden, buy corms from suppliers who label them with scientific names, and keep dried decorative corms away from pets.

Frequently Asked Questions

Sources and References

• Pet Poison Helpline: Autumn Crocus
• ASPCA: Autumn Crocus
• Merck Veterinary Manual: Houseplants and Ornamentals Toxic to Animals

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