Toxin Topic: Alsike Clover and Red Clover

Alsike clover (Trifolium hybridum) and red clover (Trifolium pratense) are valuable forage crops in North America and are often included in pasture seed mixes. However, these plants can be associated with disease conditions in all animals including horses. In addition to the risk of slaframine production, these clovers also can be associated with less common conditions in horses such as photosensitivity and liver disease. The specific toxins that cause these conditions have not yet been identified and are hypothesized to be either mycotoxins or secondary plant metabolites that are produced only under specific circumstances.

Horses with photosensitivity due to clover