What’s In a Name?

When it comes to tetanus shots, not all vaccines are created equal.

Out of habit, I always look in the refrigerator at feed stores to see what kind of tetanus vaccine they sell. More often than not, I find vials of tetanus antitoxin along with, or in the place of, tetanus toxoid. I often wonder if the person doing the ordering understands the critical differences between the two vaccines.

Let’s take a look at both.

Tetanus Toxoid
Toxoid is the typical tetanus shot, the one you should use for your horse’s initial immunization and annual booster. It is labeled “for prevention of tetanus” and takes 2 to 3 weeks to confer immunity. Since horses are prone to tetanus, give a toxoid booster at least once a year, as well as with any surgical procedure or penetrating injury.

Tetanus Antitoxin
Antitoxin is labeled “for prevention and treatment of tetanus.” It offers immediate protection from tetanus for 7 to 14 days, so only use antitoxin when you need quick and temporary immunity against tetanus in an emergency involving an unvaccinated horse. However, remember to follow up with a tetanus toxoid vaccine.

It all seems innocent enough, but tetanus antitoxin is known to cause liver damage in as little as a single dose. So read the labels and make an informed decision, regardless of what you find in your store’s refrigerator.