Production Animal Clinical Toxicology

Plants | Epidemiology | Pathogenesis | Clinical Signs | Clinical Pathology | Necropsy | Treatment | Control

Return to Production Animal Clinical Toxicology Index

Plants

• Eupatorium adenophorum - Crofton weed
• Eupatorium riparium - mist flower

Epidemiology

• only affects horses
• plant readily eaten
• plant most toxic during flowering

Pathogenesis

• toxic principle is unknown
• signs may take several years to appear, although some cases can occur within a few weeks of consumption

Clinical Signs

• first sign is cough after exertion
• rapid decrease in exercise tolerance
• chronic emphysema, rales
• depression, death

Clinical Pathology

• nonspecific

Necropsy

• uncollapsed fibrotic areas particularly dorsal areas
• abscessation
• hydrothorax

Treatment

• none

Control

• keep horses from weed; weed difficult to control