Disclosed herein are compositions for the treatment of a disease in an animal including yeast extract of Saccharomyces cerevisiae, Bacillus licheniformis or Bacillus subtilis spores, and a carrier. Also included are animal feed compositions including the composition for the prevention, control and/or treatment of a disease in an animal and an animal's food/feed. The compositions are useful to prevent, control, and treat diseases such as necrotic enteritis in poultry when used in combination with an anticoccidal ionophore or coccidiosis vaccine.