To provide a drug for animals comprising Glycyrrhizae Radix, Cinnamomi Cortex and/or Citri Leiocarpae Exocarpium, especially the Glycyrrhizae Radix, Cinnamomi Cortex and/or Citri Leiocarpae Exocarpium and a shell and to provide the drug for the animals having remarkable effects on a growth ratio, body weight gain, etc., of the animals, especially livestock, especially a medicine for controlling intestinal function for the animals, an immune strength enhancer for intestinal canals, an anti-stress agent and an improving agent for physical constitution.

The drug for the animals is characterized as comprising the the Glycyrrhizae Radix, Cinnamomi Cortex and/or Citri Leiocarpae Exocarpium, especially the Glycyrrhizae Radix, Cinnamomi Cortex and/or Citri Leiocarpae Exocarpium and the shell.