Tetanus Toxoid is administered to the animal to help build an immunity to Tetanus. After the injection, the Toxoid will start to take effect approximately 10 to 25 days, which is the time it takes tetanus to show up in the animal if present. The injection will stay in the system up to 2 to 3 months.
Tetanus Antitoxin is administered to the animal if tetanus is present in the animal already or you suspect the animal of getting it. This antitoxin takes effect almost immediately after the injection and only stays in the system for up to 10 days.