Sulphadimidine bolus is a veterinary medication that contains the active ingredient sulphadimidine, which belongs to the class of sulfonamide antibiotics. It is commonly used in livestock and companion animals to treat and prevent bacterial infections. The bolus form refers to a solid tablet or capsule that is administered orally.Sulphadimidine works by inhibiting the growth and reproduction of bacteria, thereby helping to eliminate the infection. It is effective against a wide range of gram-positive and gram-negative bacteria, including those causing respiratory, gastrointestinal, and urinary tract infections in animals.