Trisulfa Pill is a veterinary tablet that combines two active ingredients, trimethoprim and sulfamethoxazole (a sulfonamide), in one product. This combination is an antibacterial commonly used in poultry, gamefowl and pigeons. It is supplied as a box of 100 tablets. Use only as directed on the product label or by a veterinarian, observe the stated withdrawal periods and keep the product in a cool, dry place away from direct sunlight and out of the reach of children.