Production Animal Clinical Toxicology

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

Return to Production Animal Clinical Toxicology Index

Return to Production Animal Clinical Toxicology Index

Plants

• Indigofera linnaei - Birdsville indigo

Epidemiology

animal factors

• only horses
• only when animals receive little or no supplementary feeding

plant/environmental factors

• mostly during dry season (winter spring) when it is green
• toxic green or dry
• not a dominant plant in environment

Pathogenesis

• amino acids acting as arginine antagonists are thought to be involved, but mechanisms uncertain
• supplementation with arginine-rich foods (eg. peanut meal, gelatine, lucerne) prevents disease

Clinical Signs

• animals need to graze plant for 10 days before signs appear
• horses become dull, won't seek shade, stand alone
• inappetent
• progressive incoordination with front legs extended in an exaggerated manner
• hocks not flexed; anterior surface of hind hooves are dragged
• head, tail held high
• after stress or at a canter animal loses control of hind-quarters and will go down
• terminal recumbency

Clinical Pathology

• nonspecific

Necropsy

• nonspecific

Diagnosis

• access to plants, clinical signs

Treatment

• dosing with gelatine promising

Control

• prevention by supplementary feeding with arginine-rich feeds
• fence to prevent access by horses
• graze affected pastures with other herbivores