Investigation of toxicosis caused by Malva parviflora was required after 4 horses from the same farm developed severe muscle fasciculations, tachycardia, sweating and periods of recumbency leading to death or euthanasia after ingesting the plant.
Bauquier, J., Stent, A., Gibney, J., Jerrett, I., White, J., Tennent-Brown, B., Pearce, A., & Pitt, J. (2017). Evidence for marsh mallow (Malva parviflora) toxicosis causing myocardial disease and myopathy in four horses. Equine Veterinary Journal, 49(3), 307-313. https://doi.org/10.1111/evj.12604