Used primarily as a veterinary antimicrobial agent, especially in poultry and livestock. It works by inhibiting bacterial dihydrofolate reductase, disrupting folate synthesis and thereby preventing the growth of susceptible microorganisms. Commonly administered in combination with sulfonamides to enhance antibacterial effect through sequential blockade of the folic acid pathway. Found in treatments for respiratory, gastrointestinal, and systemic bacterial infections in animals. Also used as a feed additive to promote growth and prevent disease in intensive farming operations. Its use is restricted to non-food-producing animals or with withdrawal periods in food animals to avoid residues in meat and milk.