Tetanus vaccination starts with an initial course of two injections given 4-6 weeks apart. Side effects are not common, but horses may rarely become stiff or sore around the site of injection. Following the initial course, booster injections should be given at least every one to three years, depending on the vaccine manufacturer’s instructions.
If your horse is not fully vaccinated against tetanus, then an injection of tetanus ‘antitoxin’ should be given if your horse gets a cut. This antitoxin is not a vaccination but it will stop any toxin produced by the bacteria from attacking the nerves and causing paralysis. Once the antitoxin has worn off (after just a few days) your horse will be unprotected again, and should be vaccinated against tetanus as soon as possible.