Toxic feed constituents in the horse

Area of Science:

• Veterinary Toxicology
• Equine Medicine
• Animal Nutrition

Background:

• Dietary poisonings in horses stem from diverse natural and man-made sources.
• Common man-made causes include feed mixing errors and accidental ingestion of feed intended for other species.
• Ionophore feed additives and antibacterial agents are particularly toxic to horses.

Purpose of the Study:

• To highlight the toxicological risks of specific feed components in horses.
• To describe the clinical and pathological effects of ionophore and antibacterial poisonings.
• To emphasize the importance of accurate diagnosis through sample analysis.

Main Methods:

• Review of clinical, clinicopathologic, and pathological findings in horses with feed-associated poisonings.
• Analysis of toxicological data related to ionophores and antibacterials in equine diets.
• Case study review focusing on diagnostic procedures.

Main Results:

• Ionophore exposure leads to clinical, clinicopathologic, and pathological changes in cardiac, muscular, and neurological tissues.
• Acute ionophore toxicity can result in chronic cardiac dysfunction.
• Antibacterial agents alter gut microbiota, leading to toxin liberation, mucosal damage, and systemic effects.

Conclusions:

• Feed-associated poisonings, particularly from ionophores and antibacterials, pose significant health risks to horses.
• Understanding the mechanisms of toxicity is crucial for effective treatment and prevention.
• Accurate and timely laboratory analysis of samples is critical for diagnosing feed-associated poisonings in horses.