Is Lime Fertilizer Poisonous to Animals?

Horses can be poisoned by grazing too soon in pastures treated with lime fertilizer.

Lime is used to sweeten, or reduce the acidity of, the soil. The details of a given lime product's manufacturing determine whether it presents a poison hazard to your pets and livestock.

Agricultural Lime

Powdered limestone rock, also known as agricultural lime, isn't considered toxic.

Quick Lime

Heating lime produces the more reactive quick lime (burnt lime). It can irritate the skin, so keep it out of the reach of pets and small children.

Calcium Cyanamide

Also knows as lime fertilizer or lime nitrogen, calcium cyanamide irritates the skin, eyes and respiratory tract, is toxic to humans and animals, and has demonstrated moderate to high acute toxicity from oral and dermal exposure in test animals.

Dogs

To prevent accidental poisoning, either store lime fertilizer off the floor where dogs can't get at it, or in dog-proof containers. Sweep up spills promptly.

Horses

Horses should be removed from pastures where lime fertilizer is being applied and not returned until at least 1/2 inch of rainfall has occurred to wash the substance off all leaf surfaces.

References

• Lawn and Garden Hazards in Dogs
• Farm and Pasture Management
• Calcium Cyanamide

Resources

• Dog Poisoning: Be Aware of Everyday Dangers
• NC State University Cooperative Extension: Lime Questions and Answers