Tiamulin hydrogen fumarate 12.3% (w/v) in an aqueous base, an antibiotic for the treatment of swine dysentery associated with Brachyspira (formerly Serpulina or Treponema) hyodysenteriae and swine pneumonia due to Actinobacillus pleuropneumoniae, susceptible to tiamulin. Administer in the drinking water for 5 consecutive days. For use in swine only.