Toxic Garden and Landscaping Plants.

Area of Science:

• Veterinary Toxicology
• Equine Health
• Horticultural Science

Background:

• Ornamental shrubs, commonly found in North American landscapes, pose a significant toxicological risk to horses.
• Popular species such as yew (Taxus spp.), oleander (Nerium oleander), and rhododendrons/azaleas (Rhododendron spp.) are frequently implicated in equine poisonings.

Purpose of the Study:

• To highlight the prevalence and dangers of toxic ornamental shrubs in equine environments.
• To emphasize the importance of client education in preventing accidental horse poisonings.

Main Methods:

• Review of common toxic ornamental shrubs in North America.
• Analysis of exposure routes for horses, including ingestion of trimmings and contaminated hay.
• Discussion of plant palatability and ingestion factors.

Main Results:

• Yew, oleander, and rhododendrons/azaleas are identified as common toxic landscape plants for horses.
• Exposure occurs through direct ingestion of plant parts or contaminated feed.
• Some toxic plants are more readily ingested when dried or mixed with other forage.

Conclusions:

• Ingestion of toxic ornamental shrubs can lead to severe and often untreatable diseases in horses.
• Proactive client education is essential for mitigating the risk of fatal poisonings.
• Veterinarians and horse owners must be aware of and manage potential exposures to these hazardous plants.