sentences:  Cats appeared to have comparable susceptibility to rabbits, whereas dogs were ~ 1.5 x more sensitive.These early observations have been comprehensively extended by USDA researchers, who have estimated the LD50 of MLA to be ~10 mg/kg in sheep, ~ 5 mg/kg in rats, and ~2 mg/kg in cattle.Although most LD50s are usually determined from parenteral administration of the test drug, MLA is also active when taken orally.