7 THINGS YOU MAY NOT HAVE KNOWN ABOUT TETANUS

With modern vaccines and wound management practices, tetanus is almost a thing of the past. But the threat persists, so it’s wise to remember which horses are most at risk and why.

- Heather Smith Thomas with Laurie Prinz

Tetanus doesn’t grab many headlines these days. In this era of superbugs and COVID-19, a disease that can be prevented by vaccination and sensible wound management might seem almost tame.

But tetanus is anything but. Cases may not be as common as they once were, but this disease still poses a mortal threat to horses and humans alike. Clostridium tetani is an anaerobic organism, meaning it thrives in moist, low oxygen conditions. So if the environment is right in a wound contaminated with C. tetani spores, the bacteria are activated, multiply and release powerful neurotoxins that cause painful muscle contraction and spasms. Often the muscles of the head and neck are among the most obviously affected, which is why tetanus is commonly called “lockjaw.” Horses with the disease often adopt a characteristic “sawhorse” stance, as well, as muscles in the back and torso seize. More than 50 percent of horses who contract tetanus die or must be euthanatized.

Thanks to vaccination, tetanus is rare among America’s horses, but it does occur. “I wish there were zero cases,” says Simon Peek, BVSc, MRCVS, PhD, DACVIM, of the University of Wisconsin-Madison. “It’s such a horrible disease that we’d prefer to never see it again. Yet we continue to have sporadic cases, and it’s always tragic when we do.”