The invention relates to a veterinary drug for treating diarrhea of livestock. The veterinary drug is composed of the following components in parts by mass: 20-24 parts of epimedium herb, 22-26 parts of Chinese ligusticum rhizome, 18-22 parts of flower of poplar, 22-26 parts of turtle shell, 18-22 parts of fried hawthorn, 22-26 parts of ocimum basilicum, 18-22 parts of endothelium corneum gigeriae galli, 24-28 parts of willow bark, 18-22 parts of Chinese soapberry fruit, 22-26 parts of dried lotus leaf, 18-22 parts of geranium wilfordii, 22-26 parts of white hyacinth bean, 18-22 parts of glabrous sarcandra glabrous herb, 22-26 parts of concha arcae, 18-22 parts of root of roxburgh rose, 22-26 parts of root of rhododendron molle, 18-22 parts of Japanese mallotus bark, 22-26 parts of cherokee rose fruit, 18-22 parts of folium microcotis, 22-26 parts of brucea javanica, 18-22 parts of polygonum lapathifolium, 22-26 parts of herba patriniae, 18-22 parts of hemsleya sphaerocarpa and 22-26 parts of Chinese mosla herb. The veterinary drug has the efficacies of clearing away heat and toxic materials, clearing away heat and eliminating dampness, inducing diuresis, dissipating dampness, strengthening the body resistance and removing evil; all medicines cooperate with one another, so that the veterinary drug has a better treatment effect on diarrhea of livestock and has an excellent efficacy after being used clinically each time.