Lasalocid is an antibacterial agent and a coccidiostat, which is produced by strains of Streptomyces lasaliensis. Lasalocid is able to make neutral complexes with monovalent and divalent cations and transport them through apolar phase (including lipid bilayer membranes). It can transport also big organic cations like dopamine. Horses and dogs are very susceptible to the toxic effects of Lasalocid, and it should not be administered. Lasalocid was given to horses in a series of sequentially increasing single oral doses ranging between 5 and 30 mg/kg of body weight, with an appropriate washout period between treatments. The clinical signs of toxicosis observed in horses given either drug were progressive and included depression, ataxia, paresis, and paralysis with partial anorexia. Intermittent profuse sweating was observed before death in horses given monensin